usb: phy: generic: migrate to gpio_desc

usb: phy: generic: migrate to gpio_desc

Change internal gpio handling from integer gpios into gpio
descriptors. This change only addresses the internal API and
device-tree/ACPI, while the legacy platform data remains integer space
based.

This change is only build compile tested, and very prone to error. I
leave this comment for now in the commit message so that this patch gets
some testing as I'm pretty sure it's buggy.

Signed-off-by: Robert Jarzmik <[email protected]>
Acked-by: Linus Walleij <[email protected]>
Signed-off-by: Felipe Balbi <[email protected]>