Convert CONFIG_SPL_BSS_MAX_SIZE et al to Kconfig

This converts the following to Kconfig:
   CONFIG_SPL_BSS_MAX_SIZE
   CONFIG_SPL_MAX_FOOTPRINT

Note that the da850evm platforms were violating the "only use one" rule
here, and so now hard-code their BSS limit.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/imx28_xea_sb_defconfig b/configs/imx28_xea_sb_defconfig
index 91f046e..bad232c 100644
--- a/configs/imx28_xea_sb_defconfig
+++ b/configs/imx28_xea_sb_defconfig
@@ -24,6 +24,7 @@
 CONFIG_PREBOOT="run prebootcmd"
 CONFIG_BOARD_EARLY_INIT_F=y
 # CONFIG_SPL_FRAMEWORK is not set
+CONFIG_SPL_NO_BSS_LIMIT=y
 CONFIG_SPL_BOARD_INIT=y
 # CONFIG_SPL_RAW_IMAGE_SUPPORT is not set
 CONFIG_SPL_SYS_MALLOC_SIMPLE=y