RAMA M6-B and IS31FL3218 driver (#4021)

* Initial RAMA M6-B commit.

* Moved IS31FL3218 driver, minor cleanups

* Refactor, added dynamic keymap.

* Added dynamic keymaps to RAMA M6-A

* Refactor M6-A and M6-B to use common code.

* Formatting

* Cleanup

* Cleanup

* Changes from review

keyboards/rama/m6_b/info.json

@@ -0,0 +1,19 @@
+{
+  "keyboard_name": "m6-b",
+  "url": "",
+  "maintainer": "qmk",
+  "width": 3,
+  "height": 2,
+  "layouts": {
+    "LAYOUT": {
+      "layout": [
+        { "x": 0, "y": 0 },
+        { "x": 1, "y": 0 },
+        { "x": 2, "y": 0 },
+        { "x": 0, "y": 1 },
+        { "x": 1, "y": 1 },
+        { "x": 2, "y": 1 }
+      ]
+    }
+  }
+}