uboot-imx

mmc: dw_mmc: remove the duplicated header file

<asm-generic/errno.h> is already included in <errno.h>.
It can use <errno.h> instead of <asm-generic/errno.h>

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Reviewed-by: Simon Glass <sjg@chromium.org>