usb: musb: split blackfin to its own platform_driver

Just adding its own platform_driver, not really
using it yet.

Later patches will come to split power management
code from musb_core and move it completely to HW
glue layer.

Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/musb/Makefile b/drivers/usb/musb/Makefile
index d2a0129..61f46af 100644
--- a/drivers/usb/musb/Makefile
+++ b/drivers/usb/musb/Makefile
@@ -13,14 +13,12 @@
 musb_hdrc-$(CONFIG_DEBUG_FS)			+= musb_debugfs.o
 
 # Hardware Glue Layer
-
-musb_hdrc-$(CONFIG_USB_MUSB_BLACKFIN)		+= blackfin.o
-
 obj-$(CONFIG_USB_MUSB_OMAP2PLUS)		+= omap2430.o
 obj-$(CONFIG_USB_MUSB_AM35X)			+= am35x.o
 obj-$(CONFIG_USB_MUSB_TUSB6010)			+= tusb6010.o
 obj-$(CONFIG_USB_MUSB_DAVINCI)			+= davinci.o
 obj-$(CONFIG_USB_MUSB_DA8XX)			+= da8xx.o
+obj-$(CONFIG_USB_MUSB_BLACKFIN)			+= blackfin.o
 
 # the kconfig must guarantee that only one of the
 # possible I/O schemes will be enabled at a time ...