arm: rmobile: Add mmc.h for sh_mmcif of rmobile

R-Mobile and R-Car ARM SoCs use sh_mmcif as MMC host driver.
This adds arch-rmobile/mmc.h that defines mmcif_mmc_init().
Signed-off-by: NNobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
Signed-off-by: NNobuhiro Iwamatsu <iwamatsu@nigauri.org>

arch/arm/include/asm/arch-rmobile/mmc.h

+/*
+ * Renesas SuperH MMCIF driver.
+ *
+ * Copyright (C)  2014 Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
+ * Copyright (C)  2014 Renesas Electronics Corporation
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+#ifndef _RMOBILE_MMC_H_
+#define _RMOBILE_MMC_H_
+
+int mmcif_mmc_init(void);
+
+#endif /* _RMOBILE_MMC_H_ */