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/porter_defconfig b/configs/porter_defconfig
index 528dd9e..ae68633 100644
--- a/configs/porter_defconfig
+++ b/configs/porter_defconfig
@@ -29,6 +29,7 @@
 CONFIG_FIT=y
 CONFIG_BOOTDELAY=3
 CONFIG_SPL_MAX_SIZE=0x4000
+CONFIG_SPL_NO_BSS_LIMIT=y
 CONFIG_SPL_BOARD_INIT=y
 CONFIG_SPL_SYS_MALLOC_SIMPLE=y
 CONFIG_SPL_RAM_SUPPORT=y