Revert "arm64: dts: adapt to LP855X bindings changes"

commit 'ebdcfc8c ("arm64: dts: adapt to LP855X bindings changes")'
is a Tegra change, but was accidentally merged in the Qualcomm tree. The
change is reverted to avoid rebasing a large number of other changes.

This reverts commit ebdcfc8c.
Signed-off-by: Bjorn Andersson <quic_bjorande@quicinc.com>

arch/arm64/boot/dts/nvidia/tegra210-p2371-2180.dts

@@ -58,17 +58,19 @@ backlight: backlight@2c {
 			dev-ctrl = /bits/ 8 <0x80>;
 			init-brt = /bits/ 8 <0xff>;
 
+			pwm-period = <29334>;
+
 			pwms = <&pwm 0 29334>;
 			pwm-names = "lp8557";
 
 			/* boost frequency 1 MHz */
-			rom-13h {
+			rom_13h {
 				rom-addr = /bits/ 8 <0x13>;
 				rom-val = /bits/ 8 <0x01>;
 			};
 
 			/* 3 LED string */
-			rom-14h {
+			rom_14h {
 				rom-addr = /bits/ 8 <0x14>;
 				rom-val = /bits/ 8 <0x87>;
 			};