Building for avr32 leads the following build warning:
drivers/media/rc/st_rc.c:270: warning: passing argument 1 of 'IS_ERR' discards qualifiers from pointer target type
drivers/media/rc/st_rc.c:271: warning: passing argument 1 of 'PTR_ERR' discards qualifiers from pointer target type
devm_ioremap_resource() returns void __iomem *, so change 'base' and
'rx_base' definitions accordingly.