component/mariadb: add bison and m4 in PATH.

if only bison exists in PATH, we will get an error:
/path/to/bison: m4 subprocess failed: No such file or directory

component/mariadb/buildout.cfg

@@ -4,6 +4,7 @@
 [buildout]
 extends =
   ../binutils/buildout.cfg
+  ../bison/buildout.cfg
   ../bzip2/buildout.cfg
   ../cmake/buildout.cfg
   ../groonga/buildout.cfg
@@ -11,6 +12,7 @@ extends =
   ../libaio/buildout.cfg
   ../libxml2/buildout.cfg
   ../lz4/buildout.cfg
+  ../m4/buildout.cfg
   ../ncurses/buildout.cfg
   ../openssl/buildout.cfg
   ../patch/buildout.cfg
@@ -80,7 +82,7 @@ environment =
   CMAKE_INCLUDE_PATH=${bzip2:location}/include:${libaio:location}/include:${libaio:location}/include:${libxml2:location}/include:${ncurses:location}/include:${openssl:location}/include:${:pcre-location}/include:${readline5:location}/include:${xz-utils:location}/include:${zlib:location}/include:${unixodbc:location}/include:${lz4:location}/include:${snappy:location}/include:${zstd:location}/include
   CMAKE_LIBRARY_PATH=${:CMAKE_LIBRARY_PATH}
   LDFLAGS=-L${bzip2:location}/lib -L${jemalloc:location}/lib -L${libaio:location}/lib -L${:pcre-location}/lib -L${xz-utils:location}/lib -L${zlib:location}/lib -L${unixodbc:location}/lib -L${lz4:location}/lib -L${snappy:location}/lib -L${zstd:location}/lib
-  PATH=${patch:location}/bin:%(PATH)s
+  PATH=${bison:location}/bin:${m4:location}/bin:${patch:location}/bin:%(PATH)s
 post-install =
   ldd=`ldd %(location)s/lib/plugin/ha_rocksdb.so`
   for x in ${lz4:location} ${snappy:location} ${zstd:location}