usb: dwc2/s3c-hsotg: move s3c-hsotg into dwc2 directory

Moves the s3c-hsotg driver into the dwc2 directory and uses the
dwc2 defines in hw.h. Renames s3c-hsotg.c to gadget.c.

NOTE: You can build both host and peripheral as a dynamically
linked module, but be aware that if you insmod dwc2_gadget, then
rmmod it, then insmod dwc2 and dwc2_platform for host mode, this
will not work. As the step to rmmod dwc2_gadget.ko will turn off
the clock to the USB IP. The dwc2 host driver currently does not
look to turn on a clock yet. A patch to fix that will be coming
soon.

Signed-off-by: Dinh Nguyen <dinguyen@altera.com>
[ jh,rb - For gadget part only: ]
Tested-by: Jingoo Han <jg1.han@samsung.com>
Tested-by: Robert Baldyga <r.baldyga@samsung.com>
[ pz: Folded Kconfig/Makefile changes, which were originally in
  a separate patch, into this one, to avoid a build breakage.
  Modified Kconfig/Makefile changes a bit. Tested host part only. ]
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Acked-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/dwc2/Makefile

@@ -1,25 +1,28 @@
 ccflags-$(CONFIG_USB_DWC2_DEBUG)	+= -DDEBUG
 ccflags-$(CONFIG_USB_DWC2_VERBOSE)	+= -DVERBOSE_DEBUG
 
-obj-$(CONFIG_USB_DWC2)			+= dwc2.o
-
-dwc2-y					+= core.o core_intr.o
-
-# NOTE: This driver at present only implements the Host mode
-# of the controller. The existing s3c-hsotg driver supports
-# Peripheral mode, but only for the Samsung S3C platforms.
-# There are plans to merge the s3c-hsotg driver with this
-# driver in the near future to create a dual-role driver. Once
-# that is done, Host mode will become an optional feature that
-# is selected with a config option.
-
+obj-$(CONFIG_USB_DWC2_HOST)		+= dwc2.o
+dwc2-y					:= core.o core_intr.o
 dwc2-y					+= hcd.o hcd_intr.o
 dwc2-y					+= hcd_queue.o hcd_ddma.o
 
-ifneq ($(CONFIG_PCI),)
-	obj-$(CONFIG_USB_DWC2)		+= dwc2_pci.o
-endif
-obj-$(CONFIG_USB_DWC2)			+= dwc2_platform.o
+# NOTE: The previous s3c-hsotg peripheral mode only driver has been moved to
+# this location and renamed gadget.c. When building for dynamically linked
+# modules, dwc2_gadget.ko will get built for peripheral mode. For host mode,
+# the core module will be dwc2.ko, the PCI bus interface module will called
+# dwc2_pci.ko and the platform interface module will be called dwc2_platform.ko.
+# At present the host and gadget driver will be separate drivers, but there
+# are plans in the near future to create a dual-role driver.
 
-dwc2_pci-y				+= pci.o
-dwc2_platform-y				+= platform.o
+ifneq ($(CONFIG_USB_DWC2_PCI),)
+	obj-$(CONFIG_USB_DWC2_HOST)	+= dwc2_pci.o
+	dwc2_pci-y			:= pci.o
+endif
+
+ifneq ($(CONFIG_USB_DWC2_PLATFORM),)
+	obj-$(CONFIG_USB_DWC2_HOST)	+= dwc2_platform.o
+	dwc2_platform-y			:= platform.o
+endif
+
+obj-$(CONFIG_USB_DWC2_PERIPHERAL)	+= dwc2_gadget.o
+dwc2_gadget-y				:= gadget.o