gcc-cross-initial: make dependency on gnu-config-native and autoconf-native explicit

gcc-cross-initial: make dependency on gnu-config-native and autoconf-native explicit

When a project is configure to use sstate cache and has the host tool sysroot
cleaned, gcc-cross-initial may fail to be configured due to lack of
gnu-configize tool.

gcc-cross-initial recipe has autotools dependency inhibited, and the same flag
variable also excludes the gnu-config-native.  Though there is an indirect
dependency through libmpc-native, it's not safe with sstate cache being used.

Moreover, gnu-config-native requires a perl package from autoconf-native to
run, otherwise it will fail with "Can't locate Autom4te/ChannelDefs.pm in @INC"
message.

This patch makes both dependencies explicit for gcc-cross-initial's
configuration.

(From OE-Core rev: 18a913e54b40a1654d0967290088be5e7fcdd6f6)

Signed-off-by: Yuanjie Huang <yuanjie.huang@windriver.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>