ARM: dts: dra7x-evm: Align GPIO hog names with dt-schema

The dt-schema for nxp,pcf8575 expects GPIO hogs node names to end with a
'hog' suffix.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>