Update board.md

Signed-off-by: Vincent1-python <pywei201209@163.com>

Author: Vincent1-python

ports/esp32/boards/ESP32_GENERIC_P4_WIFI/board.md

@@ -1,18 +1 @@
-The following files are firmware that should work on most ESP32-based boards
-with 4MiB of flash, including WROOM WROVER, SOLO, PICO, and MINI modules.
-
-This board has multiple variants available:
-
-* If your board is based on a WROVER module, or otherwise has SPIRAM (also known
-  as PSRAM) then it's recommended to use the "spiram" variant. Look for heading
-  **Support for SPIRAM / WROVER)**.
-* If your board has a ESP32-D2WD chip (with only 2MiB flash) then use the "d2wd"
-  variant. Look for heading **ESP32 D2WD**.
-* If your board has a single-core ESP32 (e.g. the "SOLO" modules) then choose
-  the "unicore" variant. Look for heading **ESP32 Unicore**.
-* If you'd like to perform Over-the-Air updates of the MicroPython firmware,
-  then choose the "ota" variant. This variant has less room in the flash for
-  Python files as a result of supporting OTA. Look for heading **Support for
-  OTA**.
-
-Otherwise, download the generic variant (under the first heading below).
+The following firmware is applicable to most development boards based on ESP32-P4, and the development boards must be equipped with at least 16 MiB external SPI Flash.