Convert CONFIG_SYS_I2C_SPEED et al to Kconfig

This converts the following to Kconfig:
   CONFIG_SYS_I2C_SPEED
   CONFIG_SYS_I2C_SLAVE

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig
index 7bc0740..fb7736c 100644
--- a/drivers/i2c/Kconfig
+++ b/drivers/i2c/Kconfig
@@ -423,20 +423,6 @@
 	help
 	  Add support for the OMAP2+ I2C driver.
 
-if SYS_I2C_OMAP24XX
-config SYS_I2C_SLAVE
-	int "I2C Slave addr channel 0"
-	default 1
-	help
-	  OMAP24xx I2C Slave address channel 0
-
-config SYS_I2C_SPEED
-	int "I2C Slave channel 0 speed"
-	default 100000
-	help
-	  OMAP24xx Slave speed channel 0
-endif
-
 config SYS_I2C_RCAR_I2C
 	bool "Renesas RCar I2C driver"
 	depends on (RCAR_GEN3 || RCAR_GEN2) && DM_I2C
@@ -573,6 +559,25 @@
 	  by the BPMP, and can only be accessed by the main CPU via IPC
 	  requests to the BPMP. This driver covers the latter case.
 
+config SYS_I2C_SLAVE
+	hex "I2C Slave address channel (all buses)"
+	depends on SYS_I2C_LEGACY || SPL_SYS_I2C_LEGACY || TPL_SYS_I2C_LEGACY
+	default 0xfe
+	help
+	  I2C Slave address channel 0 for all buses in the legacy drivers.
+	  Many boards/controllers/drivers don't support an I2C slave
+	  interface so provide a default slave address for them for use in
+	  common code.  A real value for CONFIG_SYS_I2C_SLAVE should be
+	  defined for any board which does support a slave interface and
+	  this default used otherwise.
+
+config SYS_I2C_SPEED
+	int "I2C Slave channel 0 speed (all buses)"
+	depends on SYS_I2C_LEGACY || SPL_SYS_I2C_LEGACY || TPL_SYS_I2C_LEGACY
+	default 100000
+	help
+	  I2C Slave speed channel 0 for all buses in the legacy drivers.
+
 config SYS_I2C_BUS_MAX
 	int "Max I2C busses"
 	depends on ARCH_KEYSTONE || ARCH_OMAP2PLUS || ARCH_SOCFPGA