msm: pcie: remove PCIe CX rail vote when releasing resources

Current PMIC API call to disable CX rail does not remove
PCIe power vote. Add another API call to successfully
remove vote when releasing this resource.

Change-Id: I5203203e10e8e690745768c241e92d298b87cc4b
Signed-off-by: Tony Truong <truong@codeaurora.org>