[Keyboard] E6V2 Bootmapper Client QMK port (#5495)

* initial commit of e6v2 bmc files

* update readme with bmc template and reset key location

* fix up the switch matrix

* add usbconfig.h file

* add i2c files

* cleanup config.h

* cleanup rules.mk and remove non atmega32a architecture code

* add an appropriate keymap for testing

* update readme with warning not to flash this hex file onto atmega32u4 e6v2

* get rgb lights working

* add QMK Configurator support for 60_ansi layout

* add hhkb support layout

* add additional layouts such as tsangan and all and included QMK Configurator support for them

* add bootmagic lite, and have it be set to Esc or the key located at k50

* update readme

* fixup spacing for LAYOUT_all electrical matrix

* add some pragma once magic

* use i2c_master instead of custom i2c.c

* remove the custom i2c.c

* restore a more valid default keymap

* add eep_rst to keymap

keyboards/exclusive/e6v2/bmc/keymaps/default/config.h

@@ -0,0 +1,19 @@
+/* Copyright 2019 MechMerlin
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+// place overrides here