Not all architectures have io memory.

Fixes:
drivers/built-in.o: In function `spmi_pmic_arb_probe':
spmi-pmic-arb.c:(.text+0x1ed399): undefined reference to `devm_ioremap_resource'
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>