mmc: sh_sdhi: Fix Kconfig entry

The Kconfig entry depends on RMOBILE, but this was renamed
to ARCH_RMOBILE in commit 1cc95f6e1b38 (ARM: Rmobile: Rename
CONFIG_RMOBILE to CONFIG_ARCH_RMOBILE) . Fix this omission.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Hiroyuki Yokoyama <hiroyuki.yokoyama.vx@renesas.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
Cc: Jaehoon Chung <jh80.chung@samsung.com>
Reviewed-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig
index 0dd4443..82b8d75 100644
--- a/drivers/mmc/Kconfig
+++ b/drivers/mmc/Kconfig
@@ -156,7 +156,7 @@
 
 config SH_SDHI
 	bool "SuperH/Renesas ARM SoCs on-chip SDHI host controller support"
-	depends on RMOBILE
+	depends on ARCH_RMOBILE
 	help
 	  Support for the on-chip SDHI host controller on SuperH/Renesas ARM SoCs platform