boards: nordic: thingy53: Remove scratch from cpunet

Removes the scratch area from the network core for this board
target, this was not used anyhow but gets rid of a configuration
that would use a non-optimal swap mode

Signed-off-by: Jamie McCrae <[email protected]>

Author: nordicjm

boards/nordic/thingy53/thingy53_nrf5340_cpunet.dts

@@ -153,17 +153,12 @@ fem_spi: &spi0 {
 
 		slot0_partition: partition@c000 {
 			label = "image-0";
-			reg = <0x0000C000 0x12000>;
+			reg = <0x0000C000 0x17000>;
 		};
 
-		slot1_partition: partition@1e000 {
+		slot1_partition: partition@23000 {
 			label = "image-1";
-			reg = <0x0001E000 0x12000>;
-		};
-
-		scratch_partition: partition@30000 {
-			label = "image-scratch";
-			reg = <0x00030000 0xa000>;
+			reg = <0x00023000 0x17000>;
 		};
 
 		storage_partition: partition@3a000 {