drm/i915/gvt: Rename mpt api {set, unset}_wp_page to {enable, disable}_page_track

The kvmgt's implementation of mpt api {set,unset}_wp_page is not real
write-protection - the data get written before invoke this two api.
As discussed, change the mpt api to match the real behavior.

Signed-off-by: Changbin Du <changbin.du@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
diff --git a/drivers/gpu/drm/i915/gvt/hypercall.h b/drivers/gpu/drm/i915/gvt/hypercall.h
index f8e77e1..cb6303e6 100644
--- a/drivers/gpu/drm/i915/gvt/hypercall.h
+++ b/drivers/gpu/drm/i915/gvt/hypercall.h
@@ -44,8 +44,8 @@ struct intel_gvt_mpt {
 	void (*detach_vgpu)(unsigned long handle);
 	int (*inject_msi)(unsigned long handle, u32 addr, u16 data);
 	unsigned long (*from_virt_to_mfn)(void *p);
-	int (*set_wp_page)(unsigned long handle, u64 gfn);
-	int (*unset_wp_page)(unsigned long handle, u64 gfn);
+	int (*enable_page_track)(unsigned long handle, u64 gfn);
+	int (*disable_page_track)(unsigned long handle, u64 gfn);
 	int (*read_gpa)(unsigned long handle, unsigned long gpa, void *buf,
 			unsigned long len);
 	int (*write_gpa)(unsigned long handle, unsigned long gpa, void *buf,