clk: qcom: clk-alpha-pll: Add support for helper functions

Introduce clk_alpha_pll_write_config and alpha_pll_check_rate_margin
helper functions to be across PLL configure functions and PLL set rate
functions.

Signed-off-by: Taniya Das <tdas@codeaurora.org>
Link: https://lore.kernel.org/r/1602873815-1677-2-git-send-email-tdas@codeaurora.org


Signed-off-by: Stephen Boyd <sboyd@kernel.org>