Convert CONFIG_SPL_BSS_START_ADDR to Kconfig

This converts the following to Kconfig:
   CONFIG_SPL_BSS_START_ADDR

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/rcar3_ulcb_defconfig b/configs/rcar3_ulcb_defconfig
index 2b7c2ea..341abe4 100644
--- a/configs/rcar3_ulcb_defconfig
+++ b/configs/rcar3_ulcb_defconfig
@@ -23,6 +23,8 @@
 CONFIG_DEFAULT_FDT_FILE="r8a77950-ulcb.dtb"
 CONFIG_SYS_MALLOC_BOOTPARAMS=y
 CONFIG_UPDATE_TFTP=y
+CONFIG_SPL_HAS_BSS_LINKER_SECTION=y
+CONFIG_SPL_BSS_START_ADDR=0xe633f000
 CONFIG_SPL_BSS_MAX_SIZE=0x1000
 # CONFIG_SPL_SHARES_INIT_SP_ADDR is not set
 CONFIG_SPL_STACK=0xe6304000