tiff: upgrade to 4.5.1

Also remove old CVE_CHECK_IGNOREs which are no longer needed due to CPE
updates.

This is a backport from master. Mickledore had one extra CVE patch that
was not on master at the time of upgrade, so it had to be manually
removed here.

Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Natasha Bailey <nat.bailey@windriver.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>