feat(bootloader): split linker scripts into memory and sections

Replaced per-target bootloader.ld.in with bootloader.memory.ld.in and
bootloader.sections.ld.in.

Common code moved to file bootloader.sections.common.ld

Unify ESP32-P4 ECO4- and ECO4+ linker scripts into one shared script
Revision-specific code is selected with CONFIG_ESP32P4_SELECTS_REV_LESS_V3

components/bootloader/subproject/main/ld/esp32/bootloader.memory.ld.in

@@ -0,0 +1,34 @@
+/*
+ * SPDX-FileCopyrightText: 2021-2025 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include "sdkconfig.h"
+
+/*
+Linker file used to link the bootloader.
+*/
+
+
+/* Simplified memory map for the bootloader
+
+   The main purpose is to make sure the bootloader can load into main memory
+   without overwriting itself.
+*/
+
+MEMORY
+{
+  /* IRAM POOL1, used for APP CPU cache. Bootloader runs from here during the final stage of loading the app because APP CPU is still held in reset, the main app enables APP CPU cache */
+  iram_loader_seg (RWX) :           org = 0x40078000, len = 0x8000  /* 32KB, APP CPU cache */
+  /* 63kB, IRAM. We skip the first 1k to prevent the entry point being
+     placed into the same range as exception vectors in the app.
+     This leads to idf_monitor decoding ROM bootloader "entry 0x40080xxx"
+     message as one of the exception vectors, which looks scary to users.
+  */
+  iram_seg (RWX) :                  org = 0x40080400, len = 0xfc00
+  /* 64k at the end of DRAM, after ROM bootloader stack */
+  dram_seg (RW) :                  	org = 0x3FFF0000, len = 0x6000
+}
+
+/*  Default entry point:  */