Kconfig: Separate AM33XX SOC config from target board config

The config option AM33XX is used in several boards and should be
defined as a stand-alone option for this SOC. We break this out
from target boards that use this SoC and common headers then enable
AM33XX on in all the boards that used these targets to eliminate any
functional change with this patch.

This is similar to what has already been done in
9de852642cae ("arm: Kconfig: Add support for AM43xx SoC specific Kconfig")
and is done for the same reasons.

Signed-off-by: Andrew F. Davis <afd@ti.com>
Acked-by: Lokesh Vutla <lokeshvutla@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>

configs/cm_t335_defconfig

 CONFIG_ARM=y
+CONFIG_AM33XX=y
 CONFIG_TARGET_CM_T335=y
 CONFIG_SPL_GPIO_SUPPORT=y
 CONFIG_SPL_LIBCOMMON_SUPPORT=y

configs/pcm051_rev1_defconfig

 CONFIG_ARM=y
+CONFIG_AM33XX=y
 CONFIG_TARGET_PCM051=y
 CONFIG_SPL_GPIO_SUPPORT=y
 CONFIG_SPL_LIBCOMMON_SUPPORT=y

configs/pcm051_rev3_defconfig

 CONFIG_ARM=y
+CONFIG_AM33XX=y
 CONFIG_TARGET_PCM051=y
 CONFIG_SPL_GPIO_SUPPORT=y
 CONFIG_SPL_LIBCOMMON_SUPPORT=y

configs/pengwyn_defconfig

 CONFIG_ARM=y
+CONFIG_AM33XX=y
 CONFIG_TARGET_PENGWYN=y
 CONFIG_SPL_GPIO_SUPPORT=y
 CONFIG_SPL_LIBCOMMON_SUPPORT=y

configs/pepper_defconfig

 CONFIG_ARM=y
+CONFIG_AM33XX=y
 CONFIG_TARGET_PEPPER=y
 CONFIG_SPL_GPIO_SUPPORT=y
 CONFIG_SPL_LIBCOMMON_SUPPORT=y

include/configs/ti_am335x_common.h

@@ -12,7 +12,6 @@
 #ifndef __CONFIG_TI_AM335X_COMMON_H__
 #define __CONFIG_TI_AM335X_COMMON_H__
 
-#define CONFIG_AM33XX
 #define CONFIG_ARCH_CPU_INIT
 #define CONFIG_MAX_RAM_BANK_SIZE	(1024 << 20)	/* 1GB */
 #define CONFIG_SYS_TIMERBASE		0x48040000	/* Use Timer2 */