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 <[e-mail]>
Cc: Min Guo <[e-mail]>
Cc: Yonglong Wu <[e-mail]>
Cc: Greg Kroah-Hartman <[e-mail]>
Cc: [e-mail]
Signed-off-by: Randy Dunlap <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/musb/Kconfig

···
 	tristate "MediaTek platforms"
 	depends on ARCH_MEDIATEK || COMPILE_TEST
 	depends on NOP_USB_XCEIV
-	depends on GENERIC_PHY
+	select GENERIC_PHY
 	select USB_ROLE_SWITCH
 
 comment "MUSB DMA mode"