dt-bindings: net: ti,cc1352p7: Add bootloader-backdoor-gpios

bootloader-backdoor-gpio (along with reset-gpio) is used to enable
bootloader backdoor for flashing new firmware.

The pin and pin level to enable bootloader backdoor is configured using
the following CCFG variables in cc1352p7:
- SET_CCFG_BL_CONFIG_BL_PIN_NO
- SET_CCFG_BL_CONFIG_BL_LEVEL

Acked-by: Conor Dooley <conor.dooley@microchip.com>
Acked-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Ayush Singh <ayush@beagleboard.org>
Reviewed-by: Dhruva Gole <d-gole@ti.com>
Link: https://lore.kernel.org/r/20240903-beagleplay_fw_upgrade-v4-1-526fc62204a7@beagleboard.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: Ayush1325

Documentation/devicetree/bindings/net/ti,cc1352p7.yaml

@@ -29,6 +29,12 @@ properties:
   reset-gpios:
     maxItems: 1
 
+  bootloader-backdoor-gpios:
+    maxItems: 1
+    description: |
+      gpios to enable bootloader backdoor in cc1352p7 bootloader to allow
+      flashing new firmware.
+
   vdds-supply: true
 
 required:
@@ -46,6 +52,7 @@ examples:
         clocks = <&sclk_hf 0>, <&sclk_lf 25>;
         clock-names = "sclk_hf", "sclk_lf";
         reset-gpios = <&pio 35 GPIO_ACTIVE_LOW>;
+        bootloader-backdoor-gpios = <&pio 36 GPIO_ACTIVE_LOW>;
         vdds-supply = <&vdds>;
       };
     };