phy: qcom-qusb2: Add support for QUSB2 V2 version

Use register layout to add additional registers present
on QUSB2 PHY V2 version for PHY initialization.
Other than new registers on V2, following two register's
offset and bit definitions are different: POWERDOWN control
and PLL_STATUS.

Signed-off-by: Manu Gautam <mgautam@codeaurora.org>
Reviewed-by: Vivek Gautam <vivek.gautam@codeaurora.org>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>