ntp: Move sntp before ntp-utils in packaging order

${PN}-utils has greedy expression of capturing all in ${bindir}
and sntp gets swept in too. This move in PACKAGES fixes the problem
and now sntp binary is packaged in sntp package itself.

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Joe MacDonald <joe.macdonald@windriver.com>