spi: coldfire-qspi: Enable clock before calling spi_master_resume

This ensures clock has been enabled before calling spi_master_resume().
while at it, also add checking return value of spi_master_suspend and
spi_master_resume because they may fail.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@linaro.org>