tests: drivers: flash: erase_blocks: use overlay to erase last page

To fully test the flash controllers, the test suite should erase
the very first pages, and the very last page to find bugs in the
extremes.

Using an overlay to update the partition layout to extend slot1 to
the end makes this possible.

Signed-off-by: Bjarki Arge Andreasen <[email protected]>

Author: bjarki-andreasen

tests/drivers/flash/erase_blocks/boards/sam4e_xpro_sam4e16e.overlay

@@ -0,0 +1,16 @@
+/*
+ * Copyright (c) 2025 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+&flash0 {
+	partitions {
+		/delete-node/ storage_partition;
+
+		slot1_partition: partition@84000 {
+			label = "image-1";
+			reg = <0x00084000 0x7C000>;
+		};
+	};
+};

tests/drivers/flash/erase_blocks/testcase.yaml

@@ -12,6 +12,7 @@ tests:
     build_only: true
     platform_allow:
       - sam_v71_xult/samv71q21
+      - sam4e_xpro/sam4e16e
       - b_u585i_iot02a
       - nrf9160dk/nrf9160
       - nrf5340dk/nrf5340/cpuapp