Add Function level EECONFIG code for EEPROM (#3084)

* Add Function level EEPROM configuration

Add kb and user functions for EEPROM, and example of how to use it.

* Bug fixes and demo

* Additional cleanup

* Add EEPROM reset macro to example

* Forgot init function in list

* Move eeconfig_init_quantum function to quantum.c and actually set default layer

* See if removing weak quantum function fixes issue

* Fix travis compile error

* Remove ifdef blocks from EECONFIG so settings are always set

* Fix for ARM EEPROM updates

* Fix merge issues

* Fix potential STM32 EEPROM issues

quantum/quantum.c

@@ -945,6 +945,9 @@ void tap_random_base64(void) {
 }
 
 void matrix_init_quantum() {
+  if (!eeconfig_is_enabled() && !eeconfig_is_disabled()) {
+    eeconfig_init();
+  }
   #ifdef BACKLIGHT_ENABLE
     backlight_init_ports();
   #endif