Revert "serial: 8250: 8250_omap: Fix possible interrupt storm"

This reverts commit 31fae7c8.

Tony writes:
	I just noticed this causes the following regression in Linux
	next when pressing a key on uart console after boot at least on
	omap3. This seems to happen on serial_port_in(port, UART_RX) in
	the quirk handling.

So let's drop this.

Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/YLCCJzkkB4N7LTQS@atomide.com
Fixes: 31fae7c8

 ("serial: 8250: 8250_omap: Fix possible interrupt storm")
Reported-by: Tony Lindgren <tony@atomide.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Vignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>