blackfin: add 2012r2 and remove 2010rc1 toolchains

Remove the old 2010RC1 toolchain and add the new 2012R2-RC2 toolchain.
On related good news the new toolchain fixes:
http://autobuild.buildroot.net/results/eac5bd4f4766d98431e72a3c81492a962c85fa98/


since it's got unshare() support now.

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>