usb: musb: select GENERIC_PHY instead of depending on it

usb: musb: select GENERIC_PHY instead of depending on it

The kconfig symbol GENERIC_PHY says:
  All the users of this framework should select this config.
and around 136 out of 138 drivers do so, so change USB_MUSB_MEDIATEK
to do so also.

This (also) fixes a long circular dependency problem for an upcoming
patch.

Fixes: 0990366bab3c ("usb: musb: Add support for MediaTek musb controller")
Cc: Bin Liu <b-liu@ti.com>
Cc: Min Guo <min.guo@mediatek.com>
Cc: Yonglong Wu <yonglong.wu@mediatek.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-mediatek@lists.infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20211005235747.5588-1-rdunlap@infradead.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>