staging: spmi: hisi-spmi-controller: Use devm_ version of ioremap().

The ioremap() was never unmapped in the probe error handling or in the
remove function.  The fix is to use the devm_ioremap() function so it
gets cleaned up automatically.

Fixes: 70f59c90 ("staging: spmi: add Hikey 970 SPMI controller driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20200918143338.GE909725@mwanda


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