serial: omap-serial: Move info message to probe function

Currently the info message about a missing wakeirq for uart is printed
every time the serial driver's startup function is called. This happens
multiple times and not just once.

This can cause lots of extra messages at boot time, slowing things down.  It is
caused by commit 2a0b965c (serial: omap: Add support for optional wake-up)
which was applied for v3.13-rc1.

This patch moves the infomessage to the probe function to display it
only once.

Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: stable <stable@vger.kernel.org> # 3.13
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>