ARM: dts: dra7: Use clksel binding for CM_CLKSEL_DPLL_GMAC

With the clkcsel binding we can drop the custom ti,bit-shift devicetree
property in favor of the standard reg property and reduce the number of
clocks to update for the make W-1 dtbs warnings.

Let's also add a comment for the clocksel clock that matches the
documentation.
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/boot/dts/ti/omap/dra7xx-clocks.dtsi

@@ -575,13 +575,21 @@ dpll_ddr_m2_ck: clock-dpll-ddr-m2-8@220 {
 		ti,invert-autoidle-bit;
 	};
 
-	dpll_gmac_byp_mux: clock-dpll-gmac-byp-mux-23@2b4 {
-		#clock-cells = <0>;
-		compatible = "ti,mux-clock";
-		clock-output-names = "dpll_gmac_byp_mux";
-		clocks = <&sys_clkin1>, <&dpll_abe_m3x2_ck>;
-		ti,bit-shift = <23>;
-		reg = <0x02b4>;
+	/* CM_CLKSEL_DPLL_GMAC */
+	clock@2b4 {
+		compatible = "ti,clksel";
+		reg = <0x2b4>;
+		#clock-cells = <2>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		dpll_gmac_byp_mux: clock@23 {
+			reg = <23>;
+			compatible = "ti,mux-clock";
+			clock-output-names = "dpll_gmac_byp_mux";
+			clocks = <&sys_clkin1>, <&dpll_abe_m3x2_ck>;
+			#clock-cells = <0>;
+		};
 	};
 
 	dpll_gmac_ck: clock@2a8 {