msm: acpuclock-krait: Port additional functionality from acpuclock-8960

The following features from acpuclock-8960 are copied to acpuclock-krait:
 - HFPLL droop controller programming
 - aux_clk_sel MUX programming at init
 - "vmin" fix-up, for enforcing limits on voltages for some CPUs
 - PLL8 support in frequency tables

This will allow for future migration of various targets from using
acpuclock-8960 to the new-and-improved acpuclock-krait driver

Change-Id: Ic1c3f1eab7caba21ea7d6d4244748b2a05d8dbb8
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>