arm: socfpga: Move firewall code to firewall file

Move firewall related code to new firewall.c, to share
code in Stratix 10 and Agilex.

SDMMC will transfer data to OCRAM in SPL. So, enable privilege for SDMMC
to allow DMA transfer to OCRAM.

Signed-off-by: Ley Foon Tan <ley.foon.tan@intel.com>
Reviewed-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
5 files changed