usb: musb: davinci: fix build breakage

usb: musb: davinci: fix build breakage

Commit 0020afb369859472a461ef4af6410732e929d402 (ARM: mach-davinci:
remove mach/memory.h) removed mach/memory.h for DaVinci which broke
DaVinci MUSB build.

mach/memory.h is not actually needed in davinci.c, so remove it.
While at it, also remove some more machine specific inclulde
files which are not needed for build.

Tested on DM644x EVM using USB card reader.

Cc: stable@vger.kernel.org # v3.2
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>