staging: mt7621-pci: convert to use 'devm_platform_ioremap_resource'

Instead of getting resources parsing from DT first and remaping
afterwards, this can be done in one step using the kernel function
'devm_platform_ioremap_resource'. Hence, update to use it.

Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Link: https://lore.kernel.org/r/20201123093637.8300-7-sergio.paracuellos@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>