drm/amd/display: Build DSC without DCN config

[Why & How]
DSC needs DCN but we are trying reduce the usage of the
DCN flag. It's easier to build the DSC code sprinkled
around DC core and the DMs and just guard the place where
DSC uses floating point code.

Since DSC is never enabled on non-DCN ASICs this won't
have any effect.
Reviewed-by: Hamza Mahfooz <Hamza.Mahfooz@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Harry Wentland <harry.wentland@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/Makefile

@@ -22,14 +22,13 @@
 #
 # Makefile for Display Core (dc) component.
 
-DC_LIBS = basics bios dml clk_mgr dce gpio irq link virtual
+DC_LIBS = basics bios dml clk_mgr dce gpio irq link virtual dsc
 
 ifdef CONFIG_DRM_AMD_DC_DCN
 
 KCOV_INSTRUMENT := n
 
 DC_LIBS += dcn20
-DC_LIBS += dsc
 DC_LIBS += dcn10
 DC_LIBS += dcn21
 DC_LIBS += dcn201

drivers/gpu/drm/amd/display/dc/dsc/rc_calc.c

@@ -39,6 +39,7 @@
  */
 void calc_rc_params(struct rc_params *rc, const struct drm_dsc_config *pps)
 {
+#if defined(CONFIG_DRM_AMD_DC_DCN)
 	enum colour_mode mode;
 	enum bits_per_comp bpc;
 	bool is_navite_422_or_420;
@@ -59,4 +60,5 @@ void calc_rc_params(struct rc_params *rc, const struct drm_dsc_config *pps)
 			   slice_width, slice_height,
 			   pps->dsc_version_minor);
 	DC_FP_END();
+#endif
 }