Remove I2CPEM workspace offset

Marlin/src/feature/I2CPositionEncoder.h

               invert              = false,
               ec                  = true;
 
-    float     axisOffset          = 0;
-
-    int32_t   axisOffsetTicks     = 0,
-              zeroOffset          = 0,
+    int32_t   zeroOffset          = 0,
               lastPosition        = 0,
               position;
 
     }
 
     FORCE_INLINE float get_position_mm() { return mm_from_count(get_position()); }
-    FORCE_INLINE int32_t get_position() { return get_raw_count() - zeroOffset - axisOffsetTicks; }
+    FORCE_INLINE int32_t get_position() { return get_raw_count() - zeroOffset; }
 
     int32_t get_axis_error_steps(const bool report);
     float get_axis_error_mm(const bool report);
 
     FORCE_INLINE int get_stepper_ticks() { return stepperTicks; }
     FORCE_INLINE void set_stepper_ticks(const int ticks) { stepperTicks = ticks; }
-
-    FORCE_INLINE float get_axis_offset() { return axisOffset; }
-    FORCE_INLINE void set_axis_offset(const float newOffset) {
-      axisOffset = newOffset;
-      axisOffsetTicks = int32_t(axisOffset * get_encoder_ticks_mm());
-    }
-
-    FORCE_INLINE void set_current_position(const float newPositionMm) {
-      set_axis_offset(get_position_mm() - newPositionMm + axisOffset);
-    }
 };
 
 class I2CPositionEncodersMgr {

Marlin/src/gcode/geometry/G92.cpp

           #if HAS_POSITION_SHIFT
             position_shift[i] += v - p; // Offset the coordinate space
             update_software_endstops((AxisEnum)i);
-
-            #if ENABLED(I2C_POSITION_ENCODERS)
-              I2CPEM.encoders[I2CPEM.idx_from_axis((AxisEnum)i)].set_axis_offset(position_shift[i]);
-            #endif
-
           #endif
         }
       #endif