drm/amd/display: Add function to create 4d19 fixed point

[Why]
Implemented for future use

Signed-off-by: Tyler DiBattista <tyler.dibattista@amd.com>
Reviewed-by: Eric Bernstein <Eric.Bernstein@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/basics/fixpt31_32.c

@@ -449,6 +449,11 @@ static inline unsigned int clamp_ux_dy(
 		return min_clamp;
 }
 
+unsigned int dc_fixpt_u4d19(struct fixed31_32 arg)
+{
+	return ux_dy(arg.value, 4, 19);
+}
+
 unsigned int dc_fixpt_u3d19(struct fixed31_32 arg)
 {
 	return ux_dy(arg.value, 3, 19);