MAINTAINERS: crypto: ccree: remove co-maintainer

The best-laid plans of mice and men often go awry.
Remove Yael C. as co-maintainer as she moved on to other endeavours.

Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>