phy: Add Amlogic Meson USB2 & USB3 Generic PHY drivers

The Amlogic Meson GXL and GXM (simple variant) embeds up to 3 USB2 PHYs
and an USB3 PHY. This patch adds drivers for these for the standard generic
PHY interface and supports the power-on/off calls and set the Host mode by
default.
They are based on the excellent work from Martin Blumenstingl merged in linux.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
index 4e9d099..119edec 100644
--- a/drivers/phy/Kconfig
+++ b/drivers/phy/Kconfig
@@ -110,4 +110,12 @@
 	  used by USB2 and USB3 Host controllers available on
 	  STiH407 SoC families.
 
+config MESON_GXL_USB_PHY
+	bool "Amlogic Meson GXL USB PHYs"
+	depends on PHY && ARCH_MESON && MESON_GXL
+	imply REGMAP
+	help
+	  This is the generic phy driver for the Amlogic Meson GXL
+	  USB2 and USB3 PHYS.
+
 endmenu