[yocto] [meta-mono] Update to 3.12.1 to address SKIP TLS / FREAK vulnerabilities

[Alex J Lennon]

Hi,

meta-mono master has been updated to build the latest Mono 3.12.1
release which addresses SKIP TLS / FREAK vulnerabilities in all prior
Mono versions >= 3.4.0.

For further details see:

http://www.mono-project.com/news/2015/03/07/mono-tls-vulnerability/

Basic testing has been performed on an i.MX6 platform running helloworld
(console) and helloworldworld (matchbox ui)

Regards,

Alex