security/libgcrypt: Update to 1.7.5

• Update to 1.7.5
• Remove files useless to install from DOCS
• Remove patch since sparc v8 is not supported on FreeBSD
• Bump library version in pkg-plist

Changelog:

https://lists.gnupg.org/pipermail/gnupg-announce/2016q4/000399.html

PR: 215236
Approved by: amdmi3 (mentor)
MFH: 2016Q4
Exp-run by: antoine