Remove stubs and live K by default

Firmware/Configuration_adv.h

@@ -295,7 +295,7 @@
 
 #ifdef LIN_ADVANCE
   #define LIN_ADVANCE_K 0  // Unit: mm compression per 1mm/s extruder speed
-  #define LA_LIVE_K        // Allow adjusting K in the Tune menu
+  //#define LA_LIVE_K      // Allow adjusting K in the Tune menu
   //#define LA_DEBUG       // If enabled, this will generate debug information output over USB.
   //#define LA_DEBUG_LOGIC // @wavexx: setup logic channels for isr debugging
 #endif

Firmware/ultralcd.cpp

@@ -6612,18 +6612,6 @@ static void lcd_colorprint_change() {
 //          redefine our custom handling functions to mimick other tunables
 #define MSG_ADVANCE_K PSTR("Advance K:")
 
-#if 1
-// TODO: this is a stub to be removed for FW >3.7.1
-const static char menu_fmt_float13_k[] PROGMEM = "%c%-13.13S%+5.3f";
-const static char menu_fmt_float13off_k[] PROGMEM = "%c%-13.13S%6.6s";
-static void lcd_advance_draw_K(char chr, float val)
-{
-    if (val <= 0)
-        lcd_printf_P(menu_fmt_float13off_k, chr, MSG_ADVANCE_K, " [off]");
-    else
-        lcd_printf_P(menu_fmt_float13_k, chr, MSG_ADVANCE_K, val);
-}
-#else
 static void lcd_advance_draw_K(char chr, float val)
 {
     if (val <= 0)
@@ -6631,7 +6619,6 @@ static void lcd_advance_draw_K(char chr, float val)
     else
         lcd_printf_P(menu_fmt_float13, chr, MSG_ADVANCE_K, val);
 }
-#endif
 
 static void lcd_advance_edit_K(void)
 {