ionic: fix type complaint in ionic_dev_cmd_clean()

Sparse seems to have gotten a little more picky lately and
we need to revisit this bit of code to make sparse happy.

warning: incorrect type in initializer (different address spaces)
   expected union ionic_dev_cmd_regs *regs
   got union ionic_dev_cmd_regs [noderef] __iomem *dev_cmd_regs
warning: incorrect type in argument 2 (different address spaces)
   expected void [noderef] __iomem *
   got unsigned int *
warning: incorrect type in argument 1 (different address spaces)
   expected void volatile [noderef] __iomem *
   got union ionic_dev_cmd *

Fixes: d701ec32 ("ionic: clean up sparse complaints")
Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>