Remove superfluous JTAG disable code (#6445)

* Remove superfluous JTAG disable code

* 32A has differently named register

* Accidentally some operators

* 32A also has different JTAG pins

* Wrap disable_jtag() in an ifndef

* Document this new define

* Rename the define, it conflicts with a LUFA thing

Also, move the ifndef wrapping to the call in keyboard_setup()

tmk_core/common/keyboard.h

@@ -57,8 +57,6 @@ static inline bool IS_RELEASED(keyevent_t event) { return (!IS_NOEVENT(event) &&
     .time = (timer_read() | 1)                          \
 }
 
-void disable_jtag(void);
-
 /* it runs once at early stage of startup before keyboard_init. */
 void keyboard_setup(void);
 /* it runs once after initializing host side protocol, debug and MCU peripherals. */