Convert CONFIG_SPL_STACK to Kconfig
This converts the following to Kconfig:
CONFIG_SPL_STACK
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/pine64-lts_defconfig b/configs/pine64-lts_defconfig
index 94c03f1..c6b4f7b 100644
--- a/configs/pine64-lts_defconfig
+++ b/configs/pine64-lts_defconfig
@@ -10,6 +10,7 @@
CONFIG_MMC_SUNXI_SLOT_EXTRA=2
CONFIG_SPL_SPI_SUNXI=y
# CONFIG_SYS_MALLOC_CLEAR_ON_INIT is not set
+CONFIG_SPL_STACK=0x54000
CONFIG_SYS_PBSIZE=1024
CONFIG_SUPPORT_EMMC_BOOT=y
CONFIG_SPI_FLASH_WINBOND=y