Second reason of OMAP4 boot failure on 2.6.31.rc6, the UART
platform data is not getting registered to kernel.
Registration was failing because of clock check failure in
omap_serial_init().
Below patch fix the same.

OMAP4 clock framework patches are still getting discussed on mailing
list so till then we need this.
Signed-off-by: Syed Rafiuddin <rafiuddin.syed@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Kevin Hilman <khilman@deeprootsystems.com>