dra7xx: Move CONS_INDEX to Kconfig and enable CONFIG_SPL_STACK_ADDR

- Move the CONS_INDEX selection out of CONFIG_SYS_EXTRA_OPTIONS and
  into Kconfig proper.
- While in here, enable CONFIG_SPL_STACK_ADDR

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/dra7xx_evm_defconfig b/configs/dra7xx_evm_defconfig
index 463a7e2..f98e7b7 100644
--- a/configs/dra7xx_evm_defconfig
+++ b/configs/dra7xx_evm_defconfig
@@ -2,7 +2,8 @@
 CONFIG_OMAP54XX=y
 CONFIG_TARGET_DRA7XX_EVM=y
 CONFIG_SPL=y
-CONFIG_SYS_EXTRA_OPTIONS="CONS_INDEX=1"
+CONFIG_SPL_STACK_R=y
+CONFIG_SPL_STACK_R_ADDR=0x82000000
 # CONFIG_CMD_IMLS is not set
 # CONFIG_CMD_FLASH is not set
 # CONFIG_CMD_SETEXPR is not set