chore(attest): update t_cose hash to latest dev branch

Update t_cose hash to have the fix
https://github.com/laurencelundblade/t_cose/commit/117159b95608ce236bd69e6384e1319d7a212107



This should fix the Code maintainability issues detected by coverity,
along with the related FORWARD_NULL errors.

Change-Id: Ib858da9885a5d3a23d27fc8982e4f42557577a24
Signed-off-by: Mate Toth-Pal <mate.toth-pal@arm.com>