usb: gadget: Gadget directory cleanup - group legacy gadgets

The drivers/usb/gadget directory contains many files.
Files which are related can be distributed into separate directories.
This patch moves the legacy gadgets (i.e. those not using configfs)
into a separate directory.
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/gadget/Makefile

 #
 # USB peripheral controller drivers
 #
-ccflags-$(CONFIG_USB_GADGET_DEBUG)	:= -DDEBUG
-ccflags-$(CONFIG_USB_GADGET_VERBOSE)	+= -DVERBOSE_DEBUG
+subdir-ccflags-$(CONFIG_USB_GADGET_DEBUG)	:= -DDEBUG
+subdir-ccflags-$(CONFIG_USB_GADGET_VERBOSE)	+= -DVERBOSE_DEBUG
 
 obj-$(CONFIG_USB_GADGET)	+= udc-core.o
 obj-$(CONFIG_USB_LIBCOMPOSITE)	+= libcomposite.o
@@ -64,42 +64,4 @@ obj-$(CONFIG_USB_F_MASS_STORAGE)+= usb_f_mass_storage.o
 usb_f_fs-y			:= f_fs.o
 obj-$(CONFIG_USB_F_FS)		+= usb_f_fs.o
 
-#
-# USB gadget drivers
-#
-g_zero-y			:= zero.o
-g_audio-y			:= audio.o
-g_ether-y			:= ether.o
-g_serial-y			:= serial.o
-g_midi-y			:= gmidi.o
-gadgetfs-y			:= inode.o
-g_mass_storage-y		:= mass_storage.o
-g_printer-y			:= printer.o
-g_cdc-y				:= cdc2.o
-g_multi-y			:= multi.o
-g_hid-y				:= hid.o
-g_dbgp-y			:= dbgp.o
-g_nokia-y			:= nokia.o
-g_webcam-y			:= webcam.o
-g_ncm-y				:= ncm.o
-g_acm_ms-y			:= acm_ms.o
-g_tcm_usb_gadget-y		:= tcm_usb_gadget.o
-
-obj-$(CONFIG_USB_ZERO)		+= g_zero.o
-obj-$(CONFIG_USB_AUDIO)		+= g_audio.o
-obj-$(CONFIG_USB_ETH)		+= g_ether.o
-obj-$(CONFIG_USB_GADGETFS)	+= gadgetfs.o
-obj-$(CONFIG_USB_FUNCTIONFS)	+= g_ffs.o
-obj-$(CONFIG_USB_MASS_STORAGE)	+= g_mass_storage.o
-obj-$(CONFIG_USB_G_SERIAL)	+= g_serial.o
-obj-$(CONFIG_USB_G_PRINTER)	+= g_printer.o
-obj-$(CONFIG_USB_MIDI_GADGET)	+= g_midi.o
-obj-$(CONFIG_USB_CDC_COMPOSITE) += g_cdc.o
-obj-$(CONFIG_USB_G_HID)		+= g_hid.o
-obj-$(CONFIG_USB_G_DBGP)	+= g_dbgp.o
-obj-$(CONFIG_USB_G_MULTI)	+= g_multi.o
-obj-$(CONFIG_USB_G_NOKIA)	+= g_nokia.o
-obj-$(CONFIG_USB_G_WEBCAM)	+= g_webcam.o
-obj-$(CONFIG_USB_G_NCM)		+= g_ncm.o
-obj-$(CONFIG_USB_G_ACM_MS)	+= g_acm_ms.o
-obj-$(CONFIG_USB_GADGET_TARGET)	+= tcm_usb_gadget.o
+obj-$(CONFIG_USB_GADGET)	+= legacy/

drivers/usb/gadget/legacy/Makefile

+#
+# USB gadget drivers
+#
+
+ccflags-y			:= -I$(PWD)/drivers/usb/gadget/
+
+g_zero-y			:= zero.o
+g_audio-y			:= audio.o
+g_ether-y			:= ether.o
+g_serial-y			:= serial.o
+g_midi-y			:= gmidi.o
+gadgetfs-y			:= inode.o
+g_mass_storage-y		:= mass_storage.o
+g_printer-y			:= printer.o
+g_cdc-y				:= cdc2.o
+g_multi-y			:= multi.o
+g_hid-y				:= hid.o
+g_dbgp-y			:= dbgp.o
+g_nokia-y			:= nokia.o
+g_webcam-y			:= webcam.o
+g_ncm-y				:= ncm.o
+g_acm_ms-y			:= acm_ms.o
+g_tcm_usb_gadget-y		:= tcm_usb_gadget.o
+
+obj-$(CONFIG_USB_ZERO)		+= g_zero.o
+obj-$(CONFIG_USB_AUDIO)		+= g_audio.o
+obj-$(CONFIG_USB_ETH)		+= g_ether.o
+obj-$(CONFIG_USB_GADGETFS)	+= gadgetfs.o
+obj-$(CONFIG_USB_FUNCTIONFS)	+= g_ffs.o
+obj-$(CONFIG_USB_MASS_STORAGE)	+= g_mass_storage.o
+obj-$(CONFIG_USB_G_SERIAL)	+= g_serial.o
+obj-$(CONFIG_USB_G_PRINTER)	+= g_printer.o
+obj-$(CONFIG_USB_MIDI_GADGET)	+= g_midi.o
+obj-$(CONFIG_USB_CDC_COMPOSITE) += g_cdc.o
+obj-$(CONFIG_USB_G_HID)		+= g_hid.o
+obj-$(CONFIG_USB_G_DBGP)	+= g_dbgp.o
+obj-$(CONFIG_USB_G_MULTI)	+= g_multi.o
+obj-$(CONFIG_USB_G_NOKIA)	+= g_nokia.o
+obj-$(CONFIG_USB_G_WEBCAM)	+= g_webcam.o
+obj-$(CONFIG_USB_G_NCM)		+= g_ncm.o
+obj-$(CONFIG_USB_G_ACM_MS)	+= g_acm_ms.o
+obj-$(CONFIG_USB_GADGET_TARGET)	+= tcm_usb_gadget.o