spi: spi-omap2-mcspi.c: fix coding style

This patch fixes some indentation errors.
Signed-off-by: NMatthias Brugger <matthias.bgg@gmail.com>
Reviewed-by: NJarkko Nikula <jarkko.nikula@bitmer.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>