Refactor use of STM32_SYSCLK (#14430)

* Refactor use of STM32_SYSCLK

* clang

tmk_core/common/chibios/_wait.h

@@ -43,8 +43,6 @@ void wait_us(uint16_t duration);
 
 #include "_wait.c"
 
-#define CPU_CLOCK STM32_SYSCLK
-
 /* For GPIOs on ARM-based MCUs, the input pins are sampled by the clock of the bus
  * to which the GPIO is connected.
  * The connected buses differ depending on the various series of MCUs.

tmk_core/common/chibios/chibios_config.h

@@ -19,6 +19,11 @@
 #    define SPLIT_USB_DETECT  // Force this on when dedicated pin is not used
 #endif
 
+// STM32 compatibility
+#if defined(MCU_STM32)
+#    define CPU_CLOCK STM32_SYSCLK
+#endif
+
 #if defined(STM32F1XX)
 #    define USE_GPIOV1
 #endif
@@ -27,14 +32,13 @@
 #    define USE_I2CV1
 #endif
 
-// teensy
+// teensy compatibility
+#if defined(MCU_KINETIS)
+#    define CPU_CLOCK KINETIS_SYSCLK_FREQUENCY
+#endif
+
 #if defined(K20x) || defined(KL2x)
 #    define USE_I2CV1
 #    define USE_I2CV1_CONTRIB  // for some reason a bunch of ChibiOS-Contrib boards only have clock_speed
 #    define USE_GPIOV1
-#    define STM32_SYSCLK KINETIS_SYSCLK_FREQUENCY
-#endif
-
-#if defined(MK66F18)
-#    define STM32_SYSCLK KINETIS_SYSCLK_FREQUENCY
 #endif