samples: bluetooth: fast_pair: input_device: Improve nRF54H20 memory map

Puts fast pair provisioning partition right before the storage partition
and sets its size to 4 KiB to avoid gaps.
Align the storage partition to a 4KiB boundary as this is the sector
size.
This alignment is needed due to a bug in the storage subsystem.
Fixes the cpuapp_rw_partitions node deletion (earlier it was done
incorrectly).

Jira: NCSDK-30269

Signed-off-by: Aleksander Strzebonski <[email protected]>

Author: alstrzebonski

samples/bluetooth/fast_pair/input_device/boards/nrf54h20dk_nrf54h20_cpuapp.overlay

@@ -5,28 +5,26 @@
  */
 
 &mram1x {
-	/delete-node/ cpuapp_rw_partitions;
+	/delete-node/ cpuapp-rw-partitions;
 
 	cpuapp_rw_partitions: cpuapp-rw-partitions {
 		compatible = "nordic,owned-partitions", "fixed-partitions";
 		status = "okay";
-		perm-read;
-		perm-write;
-		perm-secure;
+		nordic,access = <NRF_OWNER_ID_APPLICATION NRF_PERM_RWS>;
 		#address-cells = <1>;
 		#size-cells = <1>;
 
 		dfu_partition: partition@100000 {
 			reg = <0x100000 DT_SIZE_K(908)>;
 		};
 
-		storage_partition: partition@1e3000 {
-			reg = <0x1e3000 DT_SIZE_K(20)>;
+		/* Align the partition size to 4096 B to avoid gaps. */
+		bt_fast_pair_partition: partition@1e3000 {
+			reg = <0x1e3000 DT_SIZE_K(4)>;
 		};
 
-		bt_fast_pair_partition: partition@1e8fb8 {
-			label = "bt_fast_pair";
-			reg = <0x1e8fb8 0x48>;
+		storage_partition: partition@1e4000 {
+			reg = <0x1e4000 DT_SIZE_K(20)>;
 		};
 	};
 };