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/xilinx_zynqmp_virt_defconfig b/configs/xilinx_zynqmp_virt_defconfig
index 91c65c9..40c9c28 100644
--- a/configs/xilinx_zynqmp_virt_defconfig
+++ b/configs/xilinx_zynqmp_virt_defconfig
@@ -32,6 +32,7 @@
 CONFIG_BOARD_EARLY_INIT_R=y
 CONFIG_CLOCKS=y
 CONFIG_SPL_MAX_SIZE=0x40000
+CONFIG_SPL_BSS_MAX_SIZE=0x80000
 CONFIG_SPL_STACK_R=y
 CONFIG_SPL_FS_LOAD_KERNEL_NAME="atf-uboot.ub"
 CONFIG_SPL_FS_LOAD_ARGS_NAME="u-boot.bin"