package/libtirpc: drop rpcgen patches

package/libtirpc: drop rpcgen patches

rpcgen patches raise a build failure with host-libtirpc since commit
0a5a9741e03e666204d577f82d29d93ba610381b because rpcgen is not provided
by modern glibc:

rpcgen -h -o tirpc/rpcsvc/crypt.h tirpc/rpcsvc/crypt.x
make[1]: rpcgen: No such file or directory

Those patches were added to build rpcbind back in 2012 with commit
18828103cdc8b929b29f5cbc27cd771ab1a26326 however they don't seem to be
needed anymore as rpcbind builds fine without them

So drop those patches and autoreconf as well as the host-nfs-utils
dependency from the target variant.

Fixes:
 - http://autobuild.buildroot.org/results/6607cb9bec426b8c78e649484d5a149a1bf12a7f

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Reviewed-by: Petr Vorel <petr.vorel@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>