spi/omap2-mcspi: convert to the pump message infrastructure

This patch converts the OMAP SPI driver to use the SPI infrastructure
pump message queue.Also fixes the below warning.
master is unqueued, this is deprecated
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>