spi: spi_flash_probe_bus_cs() rely on DT for spi speed and mode

Now, spi_flash_probe_bus_cs() relies on DT for spi speed and mode
and logically calls spi_get_bus_and_cs(). In case spi mode and speed are
not read from DT, make usage of spi_flash_probe() instead.

To sum-up:
 - Previous call tree was:
    spi_flash_probe() -> spi_flash_probe_bus_cs() -> spi_get_bus_and_cs()

 - Current call tree is:
    spi_flash_probe() -> _spi_get_bus_and_cs()
    spi_flash_probe_bus_cs() -> spi_get_bus_and_cs()

This patch impacts the following :
  - cmd/sf.c: if spi mode and/or speed is passed in argument of
    do_spi_flash_probe(), call spi_flash_probe() otherwise call
    spi_flash_probe_bus_cs().

  - drivers/net/fm/fm.c: as by default spi speed and mode was set to
    0 and a comment indicates that speed and mode are read from DT,
    use spi_flash_probe_bus_cs().

  - drivers/net/pfe_eth/pfe_firmware.c: spi speed and mode are not read
    from DT by all platforms using this driver, so keep legacy and replace
    spi_flash_probe_bus_cs() by spi_flash_probe();

  - drivers/net/sni_netsec.c : spi speed and mode are not read from DT,
    so replace spi_flash_probe_bus_cs() by spi_flash_probe().

  - drivers/usb/gadget/max3420_udc.c: Can't find any platform which make
    usage of this driver, nevertheless, keep legacy and replace
    spi_get_bus_and_cs() by _spi_get_bus_and_cs().

  - env/sf.c: a comment indicates that speed and mode are read
    from DT. So use spi_flash_probe_bus_cs().

Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>

Cc: Marek Behun <marek.behun@nic.cz>
Cc: Jagan Teki <jagan@amarulasolutions.com>
Cc: Vignesh R <vigneshr@ti.com>
Cc: Joe Hershberger <joe.hershberger@ni.com>
Cc: Ramon Fried <rfried.dev@gmail.com>
Cc: Lukasz Majewski <lukma@denx.de>
Cc: Marek Vasut <marex@denx.de>
Cc: Wolfgang Denk <wd@denx.de>
Cc: Simon Glass <sjg@chromium.org>
Cc: Stefan Roese <sr@denx.de>
Cc: "Pali Rohár" <pali@kernel.org>
Cc: Konstantin Porotchkin <kostap@marvell.com>
Cc: Igal Liberman <igall@marvell.com>
Cc: Bin Meng <bmeng.cn@gmail.com>
Cc: Pratyush Yadav <p.yadav@ti.com>
Cc: Sean Anderson <seanga2@gmail.com>
Cc: Anji J <anji.jagarlmudi@nxp.com>
Cc: Biwen Li <biwen.li@nxp.com>
Cc: Priyanka Jain <priyanka.jain@nxp.com>
Cc: Chaitanya Sakinam <chaitanya.sakinam@nxp.com>
diff --git a/drivers/mtd/spi/sf-uclass.c b/drivers/mtd/spi/sf-uclass.c
index b45ba54..e6e650e 100644
--- a/drivers/mtd/spi/sf-uclass.c
+++ b/drivers/mtd/spi/sf-uclass.c
@@ -46,25 +46,12 @@
  * TODO(sjg@chromium.org): This is an old-style function. We should remove
  * it when all SPI flash drivers use dm
  */
-struct spi_flash *spi_flash_probe(unsigned int bus, unsigned int cs,
+struct spi_flash *spi_flash_probe(unsigned int busnum, unsigned int cs,
 				  unsigned int max_hz, unsigned int spi_mode)
 {
-	struct udevice *dev;
-
-	if (spi_flash_probe_bus_cs(bus, cs, max_hz, spi_mode, &dev))
-		return NULL;
-
-	return dev_get_uclass_priv(dev);
-}
-
-int spi_flash_probe_bus_cs(unsigned int busnum, unsigned int cs,
-			   unsigned int max_hz, unsigned int spi_mode,
-			   struct udevice **devp)
-{
 	struct spi_slave *slave;
 	struct udevice *bus;
 	char *str;
-	int ret;
 
 #if defined(CONFIG_SPL_BUILD) && CONFIG_IS_ENABLED(USE_TINY_PRINTF)
 	str = "spi_flash";
@@ -74,8 +61,22 @@
 	snprintf(name, sizeof(name), "spi_flash@%d:%d", busnum, cs);
 	str = strdup(name);
 #endif
-	ret = _spi_get_bus_and_cs(busnum, cs, max_hz, spi_mode,
-				  "jedec_spi_nor", str, &bus, &slave);
+
+	if (_spi_get_bus_and_cs(busnum, cs, max_hz, spi_mode,
+				"jedec_spi_nor", str, &bus, &slave))
+		return NULL;
+
+	return dev_get_uclass_priv(slave->dev);
+}
+
+int spi_flash_probe_bus_cs(unsigned int busnum, unsigned int cs,
+			   struct udevice **devp)
+{
+	struct spi_slave *slave;
+	struct udevice *bus;
+	int ret;
+
+	ret = spi_get_bus_and_cs(busnum, cs, &bus, &slave);
 	if (ret)
 		return ret;