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/cl-som-imx7_defconfig b/configs/cl-som-imx7_defconfig
index af7fb37..ff5c21f 100644
--- a/configs/cl-som-imx7_defconfig
+++ b/configs/cl-som-imx7_defconfig
@@ -26,6 +26,7 @@
 CONFIG_BOOTCOMMAND="echo SD boot attempt ...; run sdbootscript; run sdboot; echo eMMC boot attempt ...; run emmcbootscript; run emmcboot; echo USB boot attempt ...; run usbbootscript; "
 CONFIG_BOARD_LATE_INIT=y
 CONFIG_SPL_MAX_SIZE=0xe000
+CONFIG_SPL_HAS_BSS_LINKER_SECTION=y
 CONFIG_SPL_BSS_MAX_SIZE=0x100000
 CONFIG_SPL_BOARD_INIT=y
 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR=0x80