drivers: phy: sr-usb: do not use internal fsm for USB2 phy init

During different reboot cycles, USB PHY PLL may not always lock
during initialization and therefore can cause USB to be not usable.

Hence do not use internal FSM programming sequence for the USB
PHY initialization.

Fixes: 4dcddbb3

 ("phy: sr-usb: Add Stingray USB PHY driver")
Signed-off-by: Bharat Gooty <bharat.gooty@broadcom.com>
Signed-off-by: Rayagonda Kokatanur <rayagonda.kokatanur@broadcom.com>
Link: https://lore.kernel.org/r/20200513173947.10919-1-rayagonda.kokatanur@broadcom.com
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>