linux-phytec-ti

serial: omap: Fix IRQ handling return value

Ensure the Interrupt handling routine return IRQ_HANDLED vs
IRQ_NONE.

Signed-off-by: Ruchika Kharwar <ruchika@ti.com>
Signed-off-by: Alexander Savchenko <oleksandr.savchenko@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>