MIPS: ath79: add common USB Host Controller device

Add common platform_device and helper code to make the registration of
the built-in USB controllers easier on the board which are using them.
Also register the USB controller on the AP81 and PB44 boards.

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: Imre Kaloz <kaloz@openwrt.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2442/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/ath79/Kconfig b/arch/mips/ath79/Kconfig
index 4770741..af01669 100644
--- a/arch/mips/ath79/Kconfig
+++ b/arch/mips/ath79/Kconfig
@@ -9,6 +9,7 @@
 	select ATH79_DEV_GPIO_BUTTONS
 	select ATH79_DEV_LEDS_GPIO
 	select ATH79_DEV_SPI
+	select ATH79_DEV_USB
 	help
 	  Say 'Y' here if you want your kernel to support the
 	  Atheros AP81 reference board.
@@ -19,6 +20,7 @@
 	select ATH79_DEV_GPIO_BUTTONS
 	select ATH79_DEV_LEDS_GPIO
 	select ATH79_DEV_SPI
+	select ATH79_DEV_USB
 	help
 	  Say 'Y' here if you want your kernel to support the
 	  Atheros PB44 reference board.
@@ -52,4 +54,7 @@
 config ATH79_DEV_SPI
 	def_bool n
 
+config ATH79_DEV_USB
+	def_bool n
+
 endif