Fix direct access to device key test for small erase/program ratio

This commit fixes the failure in the "Direct access to device key" test,
when working with internal flash components, whose erase size to program
size ratio is small. In such cases, the last two sectors are not large
enough to store the device key.

Author: David Saada

features/storage/TESTS/kvstore/direct_access_devicekey_test/main.cpp

@@ -186,7 +186,7 @@ void test_direct_access_to_devicekey_tdb_flashiap_remainder()
 
 void test_direct_access_to_devicekey_tdb_last_two_sectors()
 {
-    utest_printf("Test Direct Access To DeviceKey Test Entire FlashIAP Remainder\n");
+    utest_printf("Test Direct Access To DeviceKey Test Last Two Sectors\n");
 
     uint32_t flash_bd_start_address;
     uint32_t flash_bd_end_address;
@@ -198,6 +198,18 @@ void test_direct_access_to_devicekey_tdb_last_two_sectors()
     uint32_t flash_bd_size = flash_bd_end_address - flash_bd_start_address;
 
     FlashIAPBlockDevice *flash_bd = new FlashIAPBlockDevice((bd_addr_t)flash_bd_start_address, (bd_size_t)flash_bd_size);
+    flash_bd->init();
+    uint32_t sector_addr = flash_bd->size();
+    for (int i = 0; i < 2; i++) {
+        uint32_t sector_size = flash_bd->get_erase_size(sector_addr - 1);
+        uint32_t erase_prog_ratio = sector_size / flash_bd->get_program_size();
+        if (erase_prog_ratio < 4) {
+            delete flash_bd;
+            TEST_SKIP_UNLESS_MESSAGE(false, "Test skipped. Flash program size doesn't support this test.");
+        }
+        sector_addr -= sector_size;
+    }
+    flash_bd->deinit();
 
     TDBStore *tdb = new TDBStore(flash_bd);
     // Start by Init and Reset to TDBStore