staging: media: omap1: Switch to devm_ioremap_resource

Replace calls to request_mem_region and ioremap with a direct
call to devm_ioremap_resource instead and modify error
handling.
Move the call to platform_get_resource adjacent to the call to
devm_ioremap_resource to make the connection between them more
clear.

Also remove unnecessary labels, variable initialisations and
release_mem_region iounmap from probe and remove functions.

Signed-off-by: Amitoj Kaur Chawla <amitoj1606@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>