usb: phy: snps: Turn off CXO clock from msm_hsphy_dpdm_regulator_enable

dpdm_regulator_enable() function turn on the CXO clk to program the phy
registers to put PHY in non-driving mode for charger detection. In charger
connected case phy driver voting for CXO clock in dpdm_regulator_enable
but does not disabling it which is preventing the system from
vdd minimization. Hence fix this issue by turning off the CXO clk
from dpdm_regulator_enable.

Change-Id: Ib3a04eedcef625443077199d5920884f114db82d
Signed-off-by: Chandana Kishori Chiluveru <cchiluve@codeaurora.org>