SiFive's ZSBL has initialized flash, but only 16MB of space is available.
1. add code for spi
2. add code to map flash to memory spaces
Change-Id: I106688c65ac7dd70be7479dc4691797b700682d9
Signed-off-by: Xiang Wang <merle@hardenedlinux.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/33055
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Rudolph <siro@das-labor.org>
