System: fix RTCFAST section alignment

This bugfix contains 3 fixes:
1. .rtc_dummy section is removed (not needed for C3)
2. .rtc_text section is padded with 16B for possible CPU prefetch
3. .rtc_text section is aligned to 4B boundary to comply with PMS Memprot requirements

components/esp_system/ld/esp32c3/sections.ld.in

@@ -16,26 +16,20 @@ SECTIONS
   .rtc.text :
   {
     . = ALIGN(4);
+    _rtc_fast_start = ABSOLUTE(.);
 
     mapping[rtc_text]
 
     *rtc_wake_stub*.*(.literal .text .literal.* .text.*)
     *(.rtc_text_end_test)
+
+    /* 16B padding for possible CPU prefetch and 4B alignment for PMS split lines */
+    . += _esp_memprot_prefetch_pad_size;
+    . = ALIGN(4);
+
     _rtc_text_end = ABSOLUTE(.);
   } > rtc_iram_seg
 
-  /**
-   * This section is required to skip rtc.text area because rtc_iram_seg and
-   * rtc_data_seg are reflect the same address space on different buses.
-   */
-  .rtc.dummy :
-  {
-    _rtc_dummy_start = ABSOLUTE(.);
-    _rtc_fast_start = ABSOLUTE(.);
-    . = SIZEOF(.rtc.text);
-    _rtc_dummy_end = ABSOLUTE(.);
-  } > rtc_data_seg
-
   /**
    * This section located in RTC FAST Memory area.
    * It holds data marked with RTC_FAST_ATTR attribute.
@@ -375,11 +369,11 @@ SECTIONS
   /* Marks the end of IRAM code segment */
   .iram0.text_end (NOLOAD) :
   {
+    /* iram_end_test section exists for use by Memprot unit tests only */
+    *(.iram_end_test)
     /* ESP32-C3 memprot requires 16B padding for possible CPU prefetch and 512B alignment for PMS split lines */
     . += _esp_memprot_prefetch_pad_size;
     . = ALIGN(_esp_memprot_align_size);
-    /* iram_end_test section exists for use by Memprot unit tests only */
-    *(.iram_end_test)
     _iram_text_end = ABSOLUTE(.);
   } > iram0_0_seg