M73 remaining time for MKS UI (#18326)

Marlin/src/lcd/extui/lib/mks_ui/draw_printing.cpp

 #if ENABLED(POWER_LOSS_RECOVERY)
   #include "../../../../feature/powerloss.h"
 #endif
+#if BOTH(LCD_SET_PROGRESS_MANUALLY, USE_M73_REMAINING_TIME)
+  #include "../../../ultralcd.h"
+#endif
 
 static lv_obj_t * scr;
 static lv_obj_t * labelExt1, * labelExt2, * labelFan, * labelZpos, * labelTime;
 
 void disp_print_time() {
   memset(public_buf_l, 0, sizeof(public_buf_l));
-  sprintf(public_buf_l, "%d%d:%d%d:%d%d", print_time.hours / 10, print_time.hours % 10, print_time.minutes / 10, print_time.minutes % 10, print_time.seconds / 10, print_time.seconds % 10);
+  #if BOTH(LCD_SET_PROGRESS_MANUALLY, USE_M73_REMAINING_TIME)
+    const uint32_t r = ui.get_remaining_time();
+    sprintf(public_buf_l, "%02d:%02d R", r / 3600, (r % 3600) / 60);
+  #else
+    sprintf(public_buf_l, "%d%d:%d%d:%d%d", print_time.hours / 10, print_time.hours % 10, print_time.minutes / 10, print_time.minutes % 10, print_time.seconds / 10, print_time.seconds % 10);
+  #endif
   lv_label_set_text(labelTime, public_buf_l);
 }