Don't make EEPROM size assumptions with dynamic keymaps. (#16054)

* Don't make EEPROM size assumptions with dynamic keymaps.

* Add support for checking against emulated flash, error out if someone attempts to build a board without specifying EEPROM size.

* Reorder defines so that MCU is considered last.

* Refactor EEPROM definitions for simplicity.

* Fix max sizing of kabedon/kabedon980.

* Fix max sizing of mechlovin/olly/jf.

* Fix unit tests.

* Review comments, add messages with values during build failures.

platforms/chibios/eeprom_teensy.c

@@ -1,6 +1,7 @@
 #include <ch.h>
 #include <hal.h>
 
+#include "eeprom_teensy.h"
 #include "eeconfig.h"
 
 /*************************************/
@@ -42,18 +43,6 @@
 #if defined(K20x) /* chip selection */
 /* Teensy 3.0, 3.1, 3.2; mchck; infinity keyboard */
 
-// The EEPROM is really RAM with a hardware-based backup system to
-// flash memory.  Selecting a smaller size EEPROM allows more wear
-// leveling, for higher write endurance.  If you edit this file,
-// set this to the smallest size your application can use.  Also,
-// due to Freescale's implementation, writing 16 or 32 bit words
-// (aligned to 2 or 4 byte boundaries) has twice the endurance
-// compared to writing 8 bit bytes.
-//
-#    ifndef EEPROM_SIZE
-#        define EEPROM_SIZE 32
-#    endif
-
 /*
     ^^^ Here be dragons:
         NXP AppNote AN4282 section 3.1 states that partitioning must only be done once.
@@ -350,8 +339,6 @@ void do_flash_cmd(volatile uint8_t *fstat)
 extern uint32_t __eeprom_workarea_start__;
 extern uint32_t __eeprom_workarea_end__;
 
-#    define EEPROM_SIZE 128
-
 static uint32_t flashend = 0;
 
 void eeprom_initialize(void) {