ARM: dts: omap4-droid4: Enable hdq for droid4 ds250x 1-wire battery nvmem

With "[PATCHv3] w1: omap-hdq: Simplify driver with PM runtime autosuspend"
we can read the droid4 battery information over 1-wire with this patch
with something like:

# modprobe omap_hdq
# hd /sys/bus/w1/devices/89-*/89-*/nvmem
...

Unfortunately the format of the battery data seems to be Motorola specific
and is currently unusable for battery charger unless somebody figures out
what it means.

Note that currently keeping omap_hdq module loaded will cause extra power
consumption as it seems to scan devices periodically.

Cc: Merlijn Wajer <merlijn@wizzup.org>
Cc: Pavel Machek <pavel@ucw.cz>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Tony Lindgren <tony@atomide.com>