clk: msm: alpha-pll: Add support for dynamic programming of PLLs

Update the alpha_pll_set_rate function to support dynamically
updating the pll frequency if the dynamic_update flag is defined
for the pll. Also set the HW_UPDATE_BYPASS_LOGIC bit for these
plls during handoff.

CRs-Fixed: 988270
Change-Id: I7f3527ef45cf68c3f5c41e04bfdd3ede55bbaa4d
Signed-off-by: Devesh Jhunjhunwala <deveshj@codeaurora.org>