add flag for comp screen iface to indicate relative motion eventing

src/bin/e_comp.h

@@ -74,6 +74,7 @@ typedef struct E_Comp_Screen_Iface
    Eina_Bool (*key_down)(Ecore_Event_Key *ev);
    /* is key event eaten */
    Eina_Bool (*key_up)(Ecore_Event_Key *ev);
+   Eina_Bool relative_motion : 1;
 } E_Comp_Screen_Iface;
 
 /* struct to hold canvas objects so that abi doesn't break

src/bin/e_comp_x_randr.c

@@ -21,7 +21,8 @@ E_Comp_Screen_Iface xiface =
    .init = e_comp_x_randr_init,
    .shutdown = e_comp_x_randr_shutdown,
    .create = e_comp_x_randr_create,
-   .apply = e_comp_x_randr_config_apply
+   .apply = e_comp_x_randr_config_apply,
+   .relative_motion = EINA_FALSE,
 };
 
 static void

src/modules/wl_drm/e_mod_main.c

@@ -820,6 +820,7 @@ static E_Comp_Screen_Iface drmiface =
    .dpms = _drm2_dpms,
    .key_down = _drm2_key_down,
    .key_up = _drm2_key_up,
+   .relative_motion = EINA_TRUE,
 };
 
 static Eina_Bool