dt-bindings: rng: update bindings for MT7629 SoC

Device-Tree bindings for Mediatek random number generator

found in Mediatek SoC family

found in MediaTek SoC family

Required properties:

- compatible	    : Should be

			"mediatek,mt7622-rng", 	"mediatek,mt7623-rng" : for MT7622

			"mediatek,mt7629-rng",  "mediatek,mt7623-rng" : for MT7629

			"mediatek,mt7623-rng" : for MT7623

- clocks	    : list of clock specifiers, corresponding to

		      entries in clock-names property;