mesa: Drop dead #include "sparc/sparc.h"

sparc.h was removed in when the classic drivers were removed. It only
contained a prototype for _mesa_init_all_sparc_transform_asm() which
wasn't even called by context.c. Remove the #include to fix the build on
sparc.

Fixes: e030d5ba8a ("mesa: Delete libmesa_classic")
Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/6425
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/16765>
(cherry picked from commit 27f3fb5699)

.pick_status.json

@@ -1282,7 +1282,7 @@
         "description": "mesa: Drop dead #include \"sparc/sparc.h\"",
         "nominated": true,
         "nomination_type": 1,
-        "resolution": 0,
+        "resolution": 1,
         "main_sha": null,
         "because_sha": "e030d5ba8ac321b4d75587d72a0a381bb906d70e"
     },

src/mesa/main/context.c

@@ -143,10 +143,6 @@
 #include "macros.h"
 #include "git_sha1.h"
 
-#ifdef USE_SPARC_ASM
-#include "sparc/sparc.h"
-#endif
-
 #include "compiler/glsl_types.h"
 #include "compiler/glsl/builtin_functions.h"
 #include "compiler/glsl/glsl_parser_extras.h"