Fix compiler warning sketch/tmc2130.cpp: In function 'void tmc2130_set_wave(uint8_t, uint8_t, uint8_t)':

sketch/tmc2130.cpp:921:32: warning: 'reg' may be used uninitialized in this function [-Wmaybe-uninitialized]

This was completely innocent, as reg was zeroed inside for loop.

Firmware/tmc2130.cpp

@@ -869,7 +869,7 @@ void tmc2130_set_wave(uint8_t axis, uint8_t amp, uint8_t fac1000)
 	int8_t b;                      //encoded bit value
     int8_t dA;                     //delta value
 	int i;                         //microstep index
-	uint32_t reg;                  //tmc2130 register
+	uint32_t reg = 0;              //tmc2130 register
 	tmc2130_wr_MSLUTSTART(axis, 0, amp);
 	for (i = 0; i < 256; i++)
 	{