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/sama5d3_xplained_nandflash_defconfig b/configs/sama5d3_xplained_nandflash_defconfig
index 878eca9..0fb6093 100644
--- a/configs/sama5d3_xplained_nandflash_defconfig
+++ b/configs/sama5d3_xplained_nandflash_defconfig
@@ -30,6 +30,7 @@
 CONFIG_BOOTCOMMAND="nand read 0x21000000 0x180000 0x80000;nand read 0x22000000 0x200000 0x600000;bootz 0x22000000 - 0x21000000"
 # CONFIG_DISPLAY_BOARDINFO is not set
 CONFIG_SPL_MAX_SIZE=0x18000
+CONFIG_SPL_BSS_MAX_SIZE=0x80000
 CONFIG_SPL_NAND_SUPPORT=y
 CONFIG_SPL_NAND_DRIVERS=y
 CONFIG_SPL_NAND_BASE=y