ARM: dts: at91: Kill off "simple-panel" compatibles

"simple-panel" is a Linux driver and has never been an accepted upstream
compatible string, so remove it.

Cc: Nicolas Ferre <[e-mail]>
Cc: Alexandre Belloni <[e-mail]>
Cc: Ludovic Desroches <[e-mail]>
Signed-off-by: Rob Herring <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Alexandre Belloni <[e-mail]>

arch/arm/boot/dts/at91-dvk_su60_somc_lcm.dtsi

···
 	};
 
 	panel: panel {
-		compatible = "winstar,wf70gtiagdng0", "innolux,at070tn92", "simple-panel";
+		compatible = "winstar,wf70gtiagdng0", "innolux,at070tn92";
 		backlight = <&backlight>;
 		power-supply = <&vcc_lcd_reg>;
 		#address-cells = <1>;

arch/arm/boot/dts/at91-sama5d4_ma5d4evk.dts

···
 
 	panel: panel {
 		/* Actually Ampire 800480R2 */
-		compatible = "foxlink,fl500wvr00-a0t", "simple-panel";
+		compatible = "foxlink,fl500wvr00-a0t";
 		backlight = <&backlight>;
 		#address-cells = <1>;
 		#size-cells = <0>;

arch/arm/boot/dts/at91sam9n12ek.dts

···
 	};
 
 	panel: panel {
-		compatible = "qiaodian,qd43003c0-40", "simple-panel";
+		compatible = "qiaodian,qd43003c0-40";
 		backlight = <&backlight>;
 		power-supply = <&panel_reg>;
 		#address-cells = <1>;

arch/arm/boot/dts/at91sam9x5dm.dtsi

···
 	};
 
 	panel: panel {
-		compatible = "foxlink,fl500wvr00-a0t", "simple-panel";
+		compatible = "foxlink,fl500wvr00-a0t";
 		backlight = <&backlight>;
 		power-supply = <&panel_reg>;
 		#address-cells = <1>;