serial: 8250: 8250_omap: Fix possible array out of bounds access

serial: 8250: 8250_omap: Fix possible array out of bounds access

k3_soc_devices array is missing a sentinel entry which may result in out
of bounds access as reported by kernel KASAN.

Fix this by adding a sentinel entry.

Fixes: 439c7183e5b9 ("serial: 8250: 8250_omap: Disable RX interrupt after DMA enable")
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Link: https://lore.kernel.org/r/20201111112653.2710-1-vigneshr@ti.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>