crosstool-ng: upgrade default versions
crosstool-ng: upgrade default versions

* gdb 7.2
* gmp 5.0.1
* mpfr 3.0.0
* mpc 0.8.2

sknsean/core,hundeboll/core,hundeboll/core,sknsean/core,sknsean/core,diorcety/oe-lite-core,sknsean/core,diorcety/oe-lite-core,hundeboll/core,hundeboll/core,sknsean/core