freedreno/afuc: Add missing rnn_prepdb()

It's totally not obvious, but this runs extra error checking and is
necessary for correct variant handling, and variant handling will
silently not work if it's not enabled. Add it asm.c even though it's not
strictly necessary, to prevent anyone from missing this in the future.

Missing this really should be an error.

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6140>

src/freedreno/afuc/asm.c

@@ -417,6 +417,7 @@ int main(int argc, char **argv)
 	ctx = rnndec_newcontext(db);
 
 	rnn_parsefile(db, "adreno.xml");
+	rnn_prepdb(db);
 	if (db->estatus)
 		errx(db->estatus, "failed to parse register database");
 	dom[0] = rnn_finddomain(db, name);

src/freedreno/afuc/disasm.c

@@ -816,6 +816,7 @@ int main(int argc, char **argv)
 	ctx->colors = colors ? &envy_def_colors : &envy_null_colors;
 
 	rnn_parsefile(db, "adreno.xml");
+	rnn_prepdb(db);
 	if (db->estatus)
 		errx(db->estatus, "failed to parse register database");
 	dom[0] = rnn_finddomain(db, variant);