ARM: dts: at91: update flexcom defines using include file

Replace the number in the flexcom-mode property with the define from the
include file.
This corresponds to the approach in Linux kernel.

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
diff --git a/arch/arm/dts/sam9x60ek.dts b/arch/arm/dts/sam9x60ek.dts
index 77edd59..32ffe93 100644
--- a/arch/arm/dts/sam9x60ek.dts
+++ b/arch/arm/dts/sam9x60ek.dts
@@ -7,6 +7,7 @@
  * Author: Sandeep Sheriker M <Sandeepsheriker.mallikarjun@microchip.com>
  */
 /dts-v1/;
+#include <dt-bindings/mfd/atmel-flexcom.h>
 #include "sam9x60.dtsi"
 
 / {
@@ -57,7 +58,7 @@
 			};
 
 			flx0: flexcom@f801c600 {
-				atmel,flexcom-mode = <3>;
+				atmel,flexcom-mode = <ATMEL_FLEXCOM_MODE_TWI>;
 				status = "okay";
 
 				i2c@600 {
diff --git a/arch/arm/dts/sama7g5ek.dts b/arch/arm/dts/sama7g5ek.dts
index 3a4fdd3..1c59a8a 100644
--- a/arch/arm/dts/sama7g5ek.dts
+++ b/arch/arm/dts/sama7g5ek.dts
@@ -8,6 +8,7 @@
  *		  2020, Claudiu Beznea <claudiu.beznea@microchip.com>
  */
 /dts-v1/;
+#include <dt-bindings/mfd/atmel-flexcom.h>
 #include "sama7g5.dtsi"
 #include "sama7g5-pinfunc.h"
 
@@ -64,7 +65,7 @@
 };
 
 &flx1 {
-	atmel,flexcom-mode = <3>;
+	atmel,flexcom-mode = <ATMEL_FLEXCOM_MODE_TWI>;
 	status = "okay";
 };