phy: berlin-usb: fix divider for BG2

The USB PLL divider set by the marvell,berlin2-usb-phy compatible is not
correct for BG2. We couldn't change it before because BG2Q incorrectly
used the same compatible string. Now that BG2Q's compatible is fixed,
change BG2's divider to the correct value.

Signed-off-by: Thomas Hebb <tommyhebb@gmail.com>
Tested-by: Antoine Tenart <antoine.tenart@free-electrons.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>