phy-sun4i-usb: Use bool where appropriate

We're using bool as true/false type in most places in phy-sun4i-usb.c
for consistency fixup the remaining uses of ints which are ever only
0 or 1 to be bools too.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>