Fix typo of renesas,groups in the koeslch dt. The kernel has no
renesas,gpios but this should match renesas,groups.

Noticed thanks to similar fix for Lager by Rob Taylor and Ben Dooks.
Signed-off-by: NMagnus Damm <damm@opensource.se>
Signed-off-by: NSimon Horman <horms+renesas@verge.net.au>