dra7xx: config: cleanup: moved to kconfig for CONFIG_SPL_ENV_SUPPORT

removing CONFIG_SPL_ENV_SUPPORT defined in header files
due to moved to kconfig option for CONFIG_SPL_ENV_SUPPORT

Signed-off-by: Ravi Babu <ravibabu@ti.com>

include/configs/dra7xx_evm.h

@@ -136,7 +136,6 @@
 #undef CONFIG_CMD_BOOTD
 #ifdef CONFIG_SPL_DFU_SUPPORT
 #define CONFIG_SPL_LOAD_FIT_ADDRESS 0x80200000
-#define CONFIG_SPL_ENV_SUPPORT
 #define CONFIG_SPL_HASH_SUPPORT
 #define DFU_ALT_INFO_RAM \
 	"dfu_alt_info_ram=" \