t81xx: Migrate TI81XX/TI816X/TI814X symbols to Kconfig

The symbol CONFIG_TI81XX is used for the parts that are common to the
TI816x and TI814x SoCs and are not part of CONFIG_ARCH_OMAP2PLUS nor
CONFIG_AM33XX.  It however has so few uses that we can just modify the
code to check for both and drop the symbol. The symbols CONFIG_TI816X
and CONFIG_TI814X are for the repective SoCs.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/arch/arm/mach-omap2/Kconfig b/arch/arm/mach-omap2/Kconfig
index 408b62c..d161b51 100644
--- a/arch/arm/mach-omap2/Kconfig
+++ b/arch/arm/mach-omap2/Kconfig
@@ -54,12 +54,6 @@
 	select DM_SERIAL
 	select DM_GPIO
 
-config TARGET_TI814X_EVM
-	bool "Support ti814x_evm"
-
-config TARGET_TI816X_EVM
-	bool "Support ti816x_evm"
-
 config OMAP34XX
 	bool "OMAP34XX SoC"
 	select ARM_ERRATA_430973
@@ -116,6 +110,20 @@
 	imply SPL_POWER_SUPPORT
 	imply SPL_SERIAL_SUPPORT
 
+config TI814X
+	bool "TI814X SoC"
+	help
+	  Support for AM335x SOC from Texas Instruments.
+	  The AM335x high performance SOC features a Cortex-A8
+	  ARM core and more.
+
+config TI816X
+	bool "TI816X SoC"
+	help
+	  Support for AM335x SOC from Texas Instruments.
+	  The AM335x high performance SOC features a Cortex-A8
+	  ARM core and more.
+
 config AM43XX
 	bool "AM43XX SoC"
 	imply SPL_DM