amdgpu/dc: move filter taps to being static const data (v2)

This just adds two accessor methods, and moves all the data
to static const.

v2: fix dcn build.
Signed-off-by: Dave Airlie <airlied@redhat.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dce/dce_transform.c

@@ -306,7 +306,7 @@ static const uint16_t *get_filter_coeffs_16p(int taps, struct fixed31_32 ratio)
 	else if (taps == 3)
 		return get_filter_3tap_16p(ratio);
 	else if (taps == 2)
-		return filter_2tap_16p;
+		return get_filter_2tap_16p();
 	else if (taps == 1)
 		return NULL;
 	else {

drivers/gpu/drm/amd/display/dc/dce110/dce110_transform_v.c

@@ -489,7 +489,7 @@ static const uint16_t *get_filter_coeffs_64p(int taps, struct fixed31_32 ratio)
 	if (taps == 4)
 		return get_filter_4tap_64p(ratio);
 	else if (taps == 2)
-		return filter_2tap_64p;
+		return get_filter_2tap_64p();
 	else if (taps == 1)
 		return NULL;
 	else {

drivers/gpu/drm/amd/display/dc/dcn10/dcn10_dpp_dscl.c

@@ -240,7 +240,7 @@ static const uint16_t *get_filter_coeffs_64p(int taps, struct fixed31_32 ratio)
 	else if (taps == 3)
 		return get_filter_3tap_64p(ratio);
 	else if (taps == 2)
-		return filter_2tap_64p;
+		return get_filter_2tap_64p();
 	else if (taps == 1)
 		return NULL;
 	else {

drivers/gpu/drm/amd/display/dc/inc/hw/transform.h

@@ -240,8 +240,8 @@ struct transform_funcs {
 
 };
 
-extern const uint16_t filter_2tap_16p[18];
-extern const uint16_t filter_2tap_64p[66];
+const uint16_t *get_filter_2tap_16p(void);
+const uint16_t *get_filter_2tap_64p(void);
 const uint16_t *get_filter_3tap_16p(struct fixed31_32 ratio);
 const uint16_t *get_filter_3tap_64p(struct fixed31_32 ratio);
 const uint16_t *get_filter_4tap_16p(struct fixed31_32 ratio);