Improving BKDG implementation of P-states,

Improving BKDG implementation of P-states,
CPU and northbridge frequency and voltage
handling for Fam 10 in SVI mode.

Add to init_fidvid_stage2 some step
mentioned in BKDG 2.4.2.7 that was missing . Some lines
are dead code now, but may handy if one day we support
revison E CPUs.

Signed-off-by: Xavi Drudis Ferran <xdrudis@tinet.cat>
Acked-by: Marc Jones <marcj303@gmail.com>
git-svn-id: svn://svn.coreboot.org/coreboot/trunk@6404 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1