phy: qcom: qmp-usbc: Move USB-only init to usb_power_on

phy: qcom: qmp-usbc: Move USB-only init to usb_power_on

The current implementation programs USB-specific registers in
qmp_usbc_com_init(), which is shared by both USB and DP modes. This
causes unnecessary configuration when the PHY is used for DP.

Move USB-only register setup from com_init to qmp_usbc_usb_power_on,
so it runs only for USB mode.

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Signed-off-by: Xiangxu Yin <xiangxu.yin@oss.qualcomm.com>
Link: https://patch.msgid.link/20251215-add-displayport-support-for-qcs615-platform-v8-7-cbc72c88a44e@oss.qualcomm.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>