samd/boards: Add support for the Adafruit NeoKey Trinkey board.

Tested with that board.

Signed-off-by: robert-hh <robert@hammelrath.com>

ports/samd/boards/ADAFRUIT_NEOKEY_TRINKEY/board.json

@@ -0,0 +1,18 @@
+{
+    "deploy": [
+        "../deploy.md"
+    ],
+    "docs": "",
+    "features": [
+        "RGB LED",
+        "USB"
+    ],
+    "images": [
+        "neokey_trinkey.jpg"
+    ],
+    "mcu": "samd21",
+    "product": "NeoKey Trinkey",
+    "thumbnail": "",
+    "url": "https://www.adafruit.com/product/5020",
+    "vendor": "Adafruit"
+}

ports/samd/boards/ADAFRUIT_NEOKEY_TRINKEY/mpconfigboard.h

@@ -0,0 +1,14 @@
+#define MICROPY_HW_BOARD_NAME "NeoKey Trinkey"
+#define MICROPY_HW_MCU_NAME   "SAMD21E18A"
+
+#define MICROPY_HW_DFLL_USB_SYNC    (1)
+
+// The NEOKEY board has just two accessible GPIO pins.
+// So many classes and modules are useless.
+#define MICROPY_PY_MACHINE_SOFTI2C  (0)
+#define MICROPY_PY_MACHINE_SOFTSPI  (0)
+#define MICROPY_PY_MACHINE_I2C      (0)
+#define MICROPY_PY_MACHINE_SPI      (0)
+#define MICROPY_PY_MACHINE_UART     (0)
+#define MICROPY_PY_MACHINE_ADC      (0)
+#define MICROPY_PY_MACHINE_DAC      (0)

ports/samd/boards/ADAFRUIT_NEOKEY_TRINKEY/mpconfigboard.mk

@@ -0,0 +1,4 @@
+MCU_SERIES = SAMD21
+CMSIS_MCU = SAMD21E18A
+LD_FILES = boards/samd21x18a.ld sections.ld
+TEXT0 = 0x2000

ports/samd/boards/ADAFRUIT_NEOKEY_TRINKEY/pins.csv

@@ -0,0 +1,14 @@
+# The lines contain pairs of Pin name and Pin number.
+# Pin names must be valid Python identifiers.
+# Pin numbers have the form Pxnn, with x being A, B, C or D.
+# Lines starting with # or empty lines are ignored.
+
+NEOPIXEL,PA15
+SWITCH,PA18
+TOUCH,PA07
+
+USB_DM,PA24
+USB_DP,PA25
+
+SWCLK,PA30
+SWDIO,PA31