ARM: dts: gta04: add gps support

The GTA04 has a w2sg0004 or w2sg0084 gps chip. Not detectable
which one is mounted so use the compatibility entry for w2sg0004
for all which will work for both.

Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
Reviewed-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>