drivers/intel/fsp2_0: Handle FspNotify calls

Other SOC platforms need to handle the FspNotify calls in the same way
as Apollo Lake.  Migrate the FspNotify calls into the FSP 2.0 driver.
Provide a platform callback to handle anything else that needs to be
done after the FspNotify call.

Display the MTRRs before the first call to fsp_notify.

TEST=Build and run on Galileo Gen2

Change-Id: I1ff327d77516d4ea212740c16c2514c2908758a2
Signed-off-by: Lee Leahy <leroy.p.leahy@intel.com>
Reviewed-on: https://review.coreboot.org/15855
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
3 files changed