Add board: Adafruit MatrixPortal ESP32-S3 (#8230)

* Add MatrixPortal ESP32-S3 (WIP)

* Update bootloader files, etc.

* Add MatrixPortal S3 PSRAM setup to boards.txt

variants/adafruit_matrixportal_esp32s3/partitions-8MB-tinyuf2.csv

+# ESP-IDF Partition Table
+# Name,   Type, SubType, Offset,  Size, Flags
+# bootloader.bin,,          0x1000, 32K
+# partition table,,         0x8000, 4K
+nvs,      data, nvs,      0x9000,  20K,
+otadata,  data, ota,      0xe000,  8K,
+ota_0,    app,    ota_0,   0x10000,  2048K,
+ota_1,    app,    ota_1,  0x210000,  2048K,
+uf2,      app,  factory,0x410000,  256K,
+ffat,     data, fat,    0x450000,  3776K,

variants/adafruit_matrixportal_esp32s3/pins_arduino.h

+#ifndef Pins_Arduino_h
+#define Pins_Arduino_h
+
+#include <stdint.h>
+
+#define USB_VID            0x239A
+#define USB_PID            0x8125
+#define USB_MANUFACTURER   "Adafruit"
+#define USB_PRODUCT        "MatrixPortal ESP32-S3"
+#define USB_SERIAL         "" // Empty string for MAC adddress
+
+#define EXTERNAL_NUM_INTERRUPTS 46
+#define NUM_DIGITAL_PINS        48
+#define NUM_ANALOG_INPUTS       6
+
+#define analogInputToDigitalPin(p)  (((p)<NUM_ANALOG_INPUTS)?(analogChannelToDigitalPin(p)):-1)
+#define digitalPinToInterrupt(p)    (((p)<EXTERNAL_NUM_INTERRUPTS)?(p):-1)
+#define digitalPinHasPWM(p)         (p < 46)
+
+#define LED_BUILTIN         13
+
+#define PIN_NEOPIXEL        33
+#define NEOPIXEL_NUM        1
+
+static const uint8_t TX = 18;
+static const uint8_t RX = 8;
+#define TX1 TX
+#define RX1 RX
+
+static const uint8_t SDA = 16;
+static const uint8_t SCL = 17;
+
+static const uint8_t SS   = -1;
+static const uint8_t MOSI = -1;
+static const uint8_t SCK  = -1;
+static const uint8_t MISO = -1;
+
+static const uint8_t A0 = 12;
+static const uint8_t A1 = 3;
+static const uint8_t A2 = 9;
+static const uint8_t A3 = 10;
+static const uint8_t A4 = 11;
+static const uint8_t A5 = 5; // Light
+
+static const uint8_t T3  = 3;  // Touch pin IDs map directly
+static const uint8_t T8  = 8;  // to underlying GPIO numbers NOT
+static const uint8_t T9  = 9;  // the analog numbers on board silk
+static const uint8_t T10 = 10;
+static const uint8_t T11 = 11;
+static const uint8_t T12 = 12;
+
+#endif /* Pins_Arduino_h */