clk: qcom: clk-alpha-pll: Fix the pll post div mask

The PLL_POST_DIV_MASK should be 0 to (width - 1) bits. Fix it.

Fixes: 1c354114 ("clk: qcom: support for 2 bit PLL post divider")
Cc: stable@vger.kernel.org
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Satya Priya Kakitapalli <quic_skakitap@quicinc.com>
Link: https://lore.kernel.org/r/20240731062916.2680823-2-quic_skakitap@quicinc.com


Signed-off-by: Bjorn Andersson <andersson@kernel.org>