Looks like using the UART CTS pin does not always trigger for a wake-up
when the SoC is idle.

This is probably because the modem first uses gpio_149 to signal the SoC
that data will be sent, and the CTS will only get used later when the
data transfer is starting.

Let's fix the issue by configuring the gpio_149 pad as the wakeirq for
UART. We have gpio_149 managed by the USB PHY for powering up the right
USB mode, and after that, the gpio gets recycled as the modem wake-up
pin. If needeed, the USB PHY can also later on be configured to use
gpio_149 pad as the wakeirq as a shared irq.

Let's also configure the missing properties for uart-has-rtscts and
current-speed for the modem port while at it. We already configure the
hardware flow control pins with uart1_pins pinctrl setting.

Cc: maemo-leste@lists.dyne.org
Cc: Merlijn Wajer <merlijn@wizzup.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>