mainboard/intel/leafhill: initial leafhill board changes

This commit makes the initial changes to support the Intel Leaf Hill
CRB with Apollo Lake silicon. Memory parameters and some GPIOs are set.

The google/reef directory is used as a template, and the same IFWI
stitching process as reef is used to generate a bootable image.

Apollo Lake silicon requires a boot media region called IFWI which includes
assets such as CSE firmware, PMC microcode, CPU microcode, and boot
firmware.

Change-Id: Id92f0458548e3054d86f5faa8152d58d902f4418
Signed-off-by: Brenton Dong <brenton.m.dong@intel.com>
Reviewed-on: https://review.coreboot.org/18039
Tested-by: build bot (Jenkins)
Reviewed-by: Werner Zeh <werner.zeh@siemens.com>
37 files changed