inetutils: Use alternatives to avoid manpage conflict

Fix the following manpage conflicts:
 * check_data_file_clashes: Package inetutils-doc wants to install file /usr/share/man/man1/tftp.1
	But that file is already provided by package  * tftp-hpa-doc
 * check_data_file_clashes: Package inetutils-doc wants to install file /usr/share/man/man8/tftpd.8
	But that file is already provided by package  * tftp-hpa-doc
 * check_data_file_clashes: Package netkit-telnet-doc wants to install file /usr/share/man/man8/telnetd.8
	But that file is already provided by package  * inetutils-doc

Signed-off-by: Ovidiu Panait <ovidiu.panait@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
(cherry picked from commit fc14bfd6)
Signed-off-by: Armin Kuster <akuster808@gmail.com>