fbdev: sh_mobile_lcdc: Don't confuse line size with pitch

When using the MERAM the LCDC line size needs to be programmed with a
MERAM-specific value different than the real frame buffer pitch. Fix it.

Reported-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: stable@vger.kernel.org  # for 3.4
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>