mmc: uniphier: Add support for 16bit variant

Add support for 16bit mutation of the Matsushita SD IP. Since some
registers are internally 32bit, the matsu_sd_{read,write}l() has
to special-case this 16bit variant a bit.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Jaehoon Chung <jh80.chung@samsung.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/drivers/mmc/matsushita-common.h b/drivers/mmc/matsushita-common.h
index e517a2d..c1b28a0 100644
--- a/drivers/mmc/matsushita-common.h
+++ b/drivers/mmc/matsushita-common.h
@@ -123,6 +123,7 @@
 #define MATSU_SD_CAP_DMA_INTERNAL	BIT(1)	/* have internal DMA engine */
 #define MATSU_SD_CAP_DIV1024		BIT(2)	/* divisor 1024 is available */
 #define MATSU_SD_CAP_64BIT		BIT(3)	/* Controller is 64bit */
+#define MATSU_SD_CAP_16BIT		BIT(4)	/* Controller is 16bit */
 };
 
 int matsu_sd_send_cmd(struct udevice *dev, struct mmc_cmd *cmd,