commit 3d0763c0 upstream.

The spi hangs waiting the completion of omap2_mcspi_rx_callback.
Signed-off-by: Jorge A. Ventura <jorge.araujo.ventura@gmail.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>