ARM: OMAP2+: UART: Remove uart reset function.

Remove the uart reset function which is configuring the
TX empty irq which can now be handled within omap-serial driver.

Signed-off-by: Govindraj.R <govindraj.raja@ti.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de> (for drivers/tty changes)
Signed-off-by: Kevin Hilman <khilman@ti.com>