ir3: Add missing include to ir3_parser.y

This prevents build errors in the generated ir3_parser.h when
clang-format reshuffles the header includes.

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/11801>

src/freedreno/ir3/ir3_parser.y

@@ -23,6 +23,7 @@
 
 %code requires {
 #include "ir3/ir3_assembler.h"
+#include "ir3/ir3_shader.h"
 
 struct ir3 * ir3_parse(struct ir3_shader_variant *v,
 		struct ir3_kernel_info *k, FILE *f);