Added a Receive_Abort to the Marvell serial driver

Fix occasional input overrun errors on Marvell serial driver

- If the Marvell serial driver is repeatedly started and then stopped it
  will occasionally report an input overrun error when started.

- Added a Receive_Abort to the Marvell serial driver to abort previously
  received receive errors when re-starting the receive
Acked-by: Mark A. Greer <mgreer@mvista.com>
Signed-off-by: Carlos Sanchez <csanchez@mvista.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>