esp_hw_support: Fix invalid system time if s_esp_rtc_time_us & s_rtc_last_ticks were moved around

The commit fixes the case:
If variables in RTC RAM have been moved around by the linker,
they will be filled with garbage data. Any reset other than OTA would work fine
because the variables would still be initialized from the initial bootup.

So now system time will be valid even after OTA.

Closes https://github.com/espressif/esp-idf/issues/9448

components/bootloader_support/test_apps/rtc_custom_section/pytest_rtc_mem.py

@@ -9,6 +9,7 @@ from pytest_embedded import Dut
 @pytest.mark.esp32
 @pytest.mark.esp32c3
 @pytest.mark.esp32c6
+@pytest.mark.esp32h2
 @pytest.mark.esp32s2
 @pytest.mark.esp32s3
 def test_rtc_reserved_memory(dut: Dut) -> None: