feat(intel): restructure sys mgr for Agilex

This patch is to restructure system manager. Move platform dependent
MACROs to individual platform system manager. Common system manager will
remain for those common declaration only.

Signed-off-by: Jit Loon Lim <jit.loon.lim@intel.com>
Change-Id: I2f52d3eaf47716f7dfc636bbf1a23d68a04f39cb
16 files changed