devm_ioremap_resource() does a NULL check on the 'rc' argument, so
remove the unneeded manual NULL check.

While at it, place the 'rc' assignment just before
devm_ioremap_resource() to improve readability.
Signed-off-by: NFabio Estevam <fabio.estevam@nxp.com>
Acked-by: NMarek Vasut <marek.vasut@gmail.com>
Acked-by: NVladimir Zapolskiy <vz@mleia.com>
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>