mmc: omap_hsmmc: Convert critical failure reports to dev_err

Fatal errors for the driver are not reported when just error debug
is enabled. Convert selected dev_dbg to dev_err for accurate error
reporting.

Reported-by: Benoit Cousson <b-cousson@ti.com>
Signed-off-by: Venkatraman S <svenkatr@ti.com>
Signed-off-by: Chris Ball <cjb@laptop.org>