usb: host: add xhci-exynos driver

This driver supports USB Audio offload with Co-processor.
It only cares DCBAA, Device Context, Transfer Ring, Event Ring, and ERST.
They are allocated on specific address with xhci hooks.
Co-processor could use them directly without xhci driver after then.

Signed-off-by: Daehwan Jung <dh10.jung@samsung.com>

drivers/usb/host/Kconfig

@@ -783,3 +783,12 @@ config USB_XEN_HCD
 	  by the Xen host (usually Dom0).
 	  Only needed if the kernel is running in a Xen guest and generic
 	  access to a USB device is needed.
+
+config USB_XHCI_EXYNOS
+	tristate "XHCI support for Samsung Exynos SoC Series"
+	depends on ARCH_EXYNOS || COMPILE_TEST
+	help
+	  Enable support for the Samsung Exynos SOC's on-chip XHCI
+	  controller.
+
+	  If unsure, say N.

drivers/usb/host/Makefile

@@ -86,3 +86,4 @@ obj-$(CONFIG_USB_HCD_SSB)	+= ssb-hcd.o
 obj-$(CONFIG_USB_FOTG210_HCD)	+= fotg210-hcd.o
 obj-$(CONFIG_USB_MAX3421_HCD)	+= max3421-hcd.o
 obj-$(CONFIG_USB_XEN_HCD)	+= xen-hcd.o
+obj-$(CONFIG_USB_XHCI_EXYNOS)	+= xhci-exynos.o