configure: compact ppc/sparc DRI_DIRS handling

Both arches have the same list of dri_dirs.

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Reviewed-by: Matt Turner <mattst88@gmail.com>
diff --git a/configure.ac b/configure.ac
index 5b3e007..ee6d253 100644
--- a/configure.ac
+++ b/configure.ac
@@ -990,14 +990,8 @@
         fi
 
         case "$host_cpu" in
-        powerpc*)
-            # Build only the drivers for cards that exist on PowerPC.
-            if test "x$DRI_DIRS" = "xyes"; then
-                DRI_DIRS="r200 radeon swrast"
-            fi
-            ;;
-        sparc*)
-            # Build only the drivers for cards that exist on sparc
+        powerpc* | sparc*)
+            # Build only the drivers for cards that exist on PowerPC/sparc
             if test "x$DRI_DIRS" = "xyes"; then
                 DRI_DIRS="r200 radeon swrast"
             fi