tree: Use boolean for skip_ext_gfx_scan

Change-Id: I569b9a69add341bcefe6bd5356b01a95a4e97286
Signed-off-by: Elyes Haouas <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/84154
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Jakub Czapiga <czapiga@google.com>

src/mainboard/google/rex/variants/baseboard/ovis/devicetree.cb

@@ -70,7 +70,7 @@ chip soc/intel/meteorlake
 	register "energy_perf_pref_value" = "0x73"
 
 	# Set on-board graphics as primary display
-	register "skip_ext_gfx_scan" = "1"
+	register "skip_ext_gfx_scan" = "true"
 
 	register "serial_io_uart_mode" = "{
 		[PchSerialIoIndexUART0] = PchSerialIoPci,

src/mainboard/google/rex/variants/baseboard/ovis/devicetree_pre_prod.cb

@@ -68,7 +68,7 @@ chip soc/intel/meteorlake
 	register "sagv_gear[3]" = "2"
 
 	# Set on-board graphics as primary display
-	register "skip_ext_gfx_scan" = "1"
+	register "skip_ext_gfx_scan" = "true"
 
 	register "serial_io_uart_mode" = "{
 		[PchSerialIoIndexUART0] = PchSerialIoPci,

src/mainboard/google/rex/variants/baseboard/rex/devicetree.cb

@@ -70,7 +70,7 @@ chip soc/intel/meteorlake
 	register "energy_perf_pref_value" = "0x73"
 
 	# Set on-board graphics as primary display
-	register "skip_ext_gfx_scan" = "1"
+	register "skip_ext_gfx_scan" = "true"
 
 	register "serial_io_uart_mode" = "{
 		[PchSerialIoIndexUART0] = PchSerialIoSkipInit,

src/mainboard/google/rex/variants/baseboard/rex/devicetree_pre_prod.cb

@@ -65,7 +65,7 @@ chip soc/intel/meteorlake
 	register "sagv_gear[3]" = "2"
 
 	# Set on-board graphics as primary display
-	register "skip_ext_gfx_scan" = "1"
+	register "skip_ext_gfx_scan" = "true"
 
 	register "serial_io_uart_mode" = "{
 		[PchSerialIoIndexUART0] = PchSerialIoPci,

src/soc/intel/pantherlake/chip.h

@@ -179,7 +179,7 @@ struct soc_intel_pantherlake_config {
 		IGD_SM_56MB = 0xFD,
 		IGD_SM_60MB = 0xFE,
 	} IgdDvmt50PreAlloc;
-	uint8_t skip_ext_gfx_scan;
+	bool skip_ext_gfx_scan;
 
 	/* CNVi WiFi Core Enable/Disable */
 	bool cnvi_wifi_core;