drm/amd/display: Add missing newline at end of file

"git diff" says:

    \ No newline at end of file

after modifying the file.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/modules/power/Makefile

@@ -28,4 +28,4 @@ MOD_POWER = power_helpers.o
 AMD_DAL_MOD_POWER = $(addprefix $(AMDDALPATH)/modules/power/,$(MOD_POWER))
 #$(info ************  DAL POWER MODULE MAKEFILE ************)
 
-AMD_DISPLAY_FILES += $(AMD_DAL_MOD_POWER)
+AMD_DISPLAY_FILES += $(AMD_DAL_MOD_POWER)
\ No newline at end of file