tzdata: update to 2015f

tzdata: update to 2015f

Changes affecting future time stamps

North Korea switches to +0830 on 2015-08-15.  (Thanks to Steffen Thorsen.)
The abbreviation remains "KST".  (Thanks to Robert Elz.)

Uruguay no longer observes DST.  (Thanks to Steffen Thorsen
and Pablo Camargo.)

Changes affecting past and future time stamps

Moldova starts and ends DST at 00:00 UTC, not at 01:00 UTC.
(Thanks to Roman Tudos.)

Signed-off-by: Armin Kuster <akuster808@gmail.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>