ARM: dts: am335x: t335: align GPIO hog names with dtschema

The convention for node names is to use hyphens, not underscores.
dtschema for pca95xx expects GPIO hogs to end with 'hog' prefix.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>