msm: acpuclock-krait: Enable HFPLL for init only if switching to it

The existing code left the HFPLL enabled in hfpll_init(), even if
the CPU was detected to be at a non-HFPLL rate. Correct this for
power savings between when hfpll_init() and the first runtime CPU
frequency switch happen. This also ensure votes for HFPLL
regulators are not left unnecessarily asserted.

Signed-off-by: Matt Wagantall <mattw@codeaurora.org>
Change-Id: Iaca5dc7e4769bdbd494d669726ba9b500256f793