ARM: dts: Configure wlcore wakeirq for pandaboard

With wlcore supporting optional wakeirqs, we can configure it
for pandaboard. This makes ssh connection usable with the SoC
entering deeper idle states.

Note that pandaboard already has a wakeirq configured for SDIO
dat1 pin although that is not currently used by wlcore.

Signed-off-by: Tony Lindgren <tony@atomide.com>