w1: mxc: fix build

Now that header files no longer include common.h it must be included
first.

Otherwise the build fails with errors like
	include/asm/arch/clock.h:43:1: error: unknown type name 'u32'
	 u32 imx_get_uartclk(void);

Fixes: c3dc39a2 ("arm: Don't include common.h in header files")

Signed-off-by: Martin Fuzzey <martin.fuzzey@flowbird.group>
Reviewed-by: Simon Glass <sjg@chromium.org>