mfd: Fix mc13xxx-spi merge conflict

This patch fixes conflict between commit 8ae3559
"mfd: mc13xxx workaround SPI hardware bug on i.Mx"
and commit 10c7a5d "mfd: Use devm_* APIs for mc13xxx".

commit 8ae3559 changes regmap_init_spi to regmap_init.
So now we need to use devm_regmap_init rather than devm_regmap_init_spi.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>