video: sa1100fb: use devm_ioremap_resource()

Use devm_ioremap_resource() to map the LCD controller memory region,
and remove the unnecessary cleanup for this.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>