ntp: Moving relevant files from /usr/bin to /usr/sbin

"--with-binsubdir" controls whether we use bin_PROGRAMS or
sbin_PROGRAMS while installing executable files in ntp
Makefile, in order to install all the relevant files in
/usr/sbin instead of /usr/bin, we can pass "--with-binsubdir=sbin"
in ntp configure cmdline.
Accordingly, updating the path for the files which are
contained in rpm packages.

Signed-off-by: Xufeng Zhang <xufeng.zhang@windriver.com>
Signed-off-by: Joe MacDonald <joe@deserted.net>