drm/i915/gvt: remove the unused sreg

code cleanup. sreg is not used now. remove it for code cleanness.

v3: remove unnecessary array_size in vreg's memory allocation (min he)
v2: do not allocate memory for sreg. (min he)

Reviewed-by: He, Min <min.he@intel.com>
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

drivers/gpu/drm/i915/gvt/handlers.c

@@ -3488,12 +3488,11 @@ int intel_vgpu_mmio_reg_rw(struct intel_vgpu *vgpu, unsigned int offset,
 		return mmio_info->read(vgpu, offset, pdata, bytes);
 	else {
 		u64 ro_mask = mmio_info->ro_mask;
-		u32 old_vreg = 0, old_sreg = 0;
+		u32 old_vreg = 0;
 		u64 data = 0;
 
 		if (intel_gvt_mmio_has_mode_mask(gvt, mmio_info->offset)) {
 			old_vreg = vgpu_vreg(vgpu, offset);
-			old_sreg = vgpu_sreg(vgpu, offset);
 		}
 
 		if (likely(!ro_mask))
@@ -3515,8 +3514,6 @@ int intel_vgpu_mmio_reg_rw(struct intel_vgpu *vgpu, unsigned int offset,
 
 			vgpu_vreg(vgpu, offset) = (old_vreg & ~mask)
 					| (vgpu_vreg(vgpu, offset) & mask);
-			vgpu_sreg(vgpu, offset) = (old_sreg & ~mask)
-					| (vgpu_sreg(vgpu, offset) & mask);
 		}
 	}