CC: cyassl: update to wolfssl version 3.8.0 to fix security problems

CC: cyassl: update to wolfssl version 3.8.0 to fix security problems
Backport of:
r46167: cyassl: version bump to 3.4.6
r46168: cyassl: update to wolfssl 3.6.0
r46551: cyassl: the upstream package in version 4.6.0 changed
r47791: cyassl: update to wolfSSL version 3.7.0
    This version and version 3.6.8 are fixing the following security problems:
    * CVE-2015-7744
    * CVE-2015-6925
r48616: cyassl: update to wolfssl version 3.8.0

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
git-svn-id: svn://svn.openwrt.org/openwrt/branches/chaos_calmer@48873 3c298f89-4303-0410-b956-a3cf2f4a3e73