usb: phy-generic: Delete unused platform data

The last user of the phy generic platform data was
deleted in commit 1e041b6f
("usb: dwc3: exynos: Remove dead code"). So get rid of
the platform data, which rids us of another consumer of
the legacy GPIO API at the same time. Make sure we
only inlcude <linux/gpio/consumer.h> which is all we use.

Alter the usb_phy_gen_create_phy() function prototype to
not pass any platform data as this is just hardcoded to
NULL at all locations calling it in the kernel.

Move the devm_gpiod_get* calls out of the if (of_node)
parenthesis, as these calls are generic and do not depend
on device tree, they are used by any hardware description.

Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>