The core spi driver swaps the polarity of the enable based on SPI_CS_HIGH.
The omap2 controller has an internal configuration register bit called
OMAP2_MCSPI_CHCONF_EPOL to handle active high chip selects as well.

So we have to revert swap the polarity back for the correct setting of the
OMAP2_MCSPI_CHCONF_FORCE bit in omap2_mcspi_set_cs.
Signed-off-by: NMichael Welling <mwelling@ieee.org>
Signed-off-by: NMark Brown <broonie@kernel.org>