sh_mobile_meram: Rename operations to cache_[alloc|free|update]

The MERAM operations meram_register, meram_unregister and meram_update
handle LCDC cache. In preparation for "raw" MERAM allocation, rename
them to more appropriate names.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
diff --git a/drivers/video/sh_mobile_lcdcfb.h b/drivers/video/sh_mobile_lcdcfb.h
index 5c3bddd..e53cd11 100644
--- a/drivers/video/sh_mobile_lcdcfb.h
+++ b/drivers/video/sh_mobile_lcdcfb.h
@@ -59,7 +59,7 @@
 	unsigned long *reg_offs;
 	unsigned long ldmt1r_value;
 	unsigned long enabled; /* ME and SE in LDCNT2R */
-	void *meram;
+	void *cache;
 
 	struct mutex open_lock;		/* protects the use counter */
 	int use_count;