Add Blues Cygnet and Swan R5 boards (#822)

* Add Blues Cygnet board
* Feat: Blues Swan R5 (alias)

---------
Co-authored-by: Zachary J. Fields <[email protected]>

Author: maxgerhardt

boards/blues_cygnet.json

@@ -0,0 +1,46 @@
+{
+    "build": {
+      "cpu": "cortex-m4",
+      "extra_flags": "-DSTM32L4 -DSTM32L433xx",
+      "f_cpu": "80000000L",
+      "framework_extra_flags": {
+        "arduino": "-DCUSTOM_PERIPHERAL_PINS -DARDUINO_CYGNET -DPIO_FRAMEWORK_ARDUINO_ENABLE_CDC"
+      },
+      "mcu": "stm32l433cct6",
+      "product_line": "STM32L433xx",
+      "variant": "STM32L4xx/L433C(B-C)(T-U)_L443CC(T-U)"
+    },
+    "connectivity": [
+      "can"
+    ],
+    "debug": {
+      "default_tools": [
+        "stlink"
+      ],
+      "jlink_device": "STM32L433CC",
+      "openocd_target": "stm32l4x",
+      "svd_path": "STM32L4x3.svd"
+    },
+    "frameworks": [
+      "arduino",
+      "cmsis",
+      "stm32cube",
+      "libopencm3"
+    ],
+    "name": "Blues Cygnet",
+    "upload": {
+      "maximum_ram_size": 65536,
+      "maximum_size": 262144,
+      "protocol": "dfu",
+      "protocols": [
+        "dfu",
+        "jlink",
+        "cmsis-dap",
+        "stlink",
+        "blackmagic",
+        "mbed"
+      ]
+    },
+    "url": "https://blues.com/feather-mcu/",
+    "vendor": "Blues"
+  }

boards/blues_swan_r5.json

@@ -0,0 +1,46 @@
+{
+  "build": {
+    "arduino": {
+      "variant_h": "variant_SWAN_R5.h"
+    },
+    "core": "stm32",
+    "cpu": "cortex-m4",
+    "extra_flags": "-DARDUINO_SWAN_R5 -DSTM32L4 -DSTM32L4xx -DSTM32L4R5xx",
+    "f_cpu": "120000000L",
+    "framework_extra_flags": {
+      "arduino": "-DCUSTOM_PERIPHERAL_PINS"
+    },
+    "mcu": "stm32l4r5ziy6",
+    "product_line": "STM32L4R5xx",
+    "variant": "STM32L4xx/L4R5Z(G-I)Y_L4R9Z(G-I)Y_L4S5ZIY_L4S9ZIY"
+  },
+  "connectivity": [
+    "can"
+  ],
+  "debug": {
+    "jlink_device": "STM32L4R5ZI",
+    "openocd_target": "stm32l4x",
+    "svd_path": "STM32L4R5.svd"
+  },
+  "frameworks": [
+    "arduino",
+    "stm32cube"
+  ],
+  "name": "Blues Swan R5",
+  "upload": {
+    "maximum_ram_size": 655360,
+    "maximum_size": 2097152,
+    "protocol": "stlink",
+    "protocols": [
+      "dfu",
+      "blackmagic",
+      "cmsis-dap",
+      "jlink",
+      "serial",
+      "stlink",
+      "mbed"
+    ]
+  },
+  "url": "https://blues.io/products/swan",
+  "vendor": "Blues"
+}