phy: omap-usb2: Remove unneeded ifdef CONFIG_OF guard and of_match_ptr

if !CONFIG_OF, the probe fails.
This is a dt-only driver, so the ifdef CONFIG_OF guard and of_match_ptr are
not needed.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>