ARM: imx: include ulpi.h rather than mach/ulpi.h

Rename mach-imx/include/mach/ulpi.h to mach-imx/ulpi.h, and update
users to include ulpi.h rather than mach/ulpi.h.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>