lk: calculate vco clock and divider for 8996 target

Calculate the VCO clock, n1 and n2 divider for
8996 target. This change also update pll type check
in display driver and GCDB to support multiple type of
PLLs.

Change-Id: I5aa470cba5150e1c668a60e182c30e03af2f9556
6 files changed