r600: Drop unused sbcl debug option.

Reviewed-by: Gert Wollny <gert.wollny@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/14429>

src/gallium/drivers/r600/r600_pipe.c

@@ -48,7 +48,6 @@ static const struct debug_named_value r600_debug_options[] = {
 
 	/* shader backend */
 	{ "nosb", DBG_NO_SB, "Disable sb backend for graphics shaders" },
-	{ "sbcl", DBG_SB_CS, "Enable sb backend for compute shaders" },
 	{ "sbdry", DBG_SB_DRY_RUN, "Don't use optimized bytecode (just print the dumps)" },
 	{ "sbstat", DBG_SB_STAT, "Print optimization statistics for shaders" },
 	{ "sbdump", DBG_SB_DUMP, "Print IR dumps after some optimization passes" },

src/gallium/drivers/r600/r600_pipe.h

@@ -261,7 +261,6 @@ struct r600_gs_rings_state {
 #define DBG_NO_CP_DMA		(1 << 30)
 /* shader backend */
 #define DBG_NO_SB		(1 << 21)
-#define DBG_SB_CS		(1 << 22)
 #define DBG_SB_DRY_RUN	(1 << 23)
 #define DBG_SB_STAT		(1 << 24)
 #define DBG_SB_DUMP		(1 << 25)

src/gallium/drivers/r600/sb/notes.markdown

@@ -13,7 +13,6 @@ Debugging
     There are new flags:
 
     -   **nosb** - Disable sb backend for graphics shaders
-    -   **sbcl** - Enable optimization of compute shaders (experimental)
     -   **sbdry** - Dry run, optimize but use source bytecode -
         useful if you only want to check shader dumps
         without the risk of lockups and other problems