RSB rtems-4.12 gcc-6 dependent package version numbers.

[Chris Johns]

Hi Sebastian,

Looking at 4.12 build in the RSB I see:

  mpfr		2.4.2
  mpc		0.8.1
  gmp		4.3.2

The 4.11 gcc-4.9.3 is using:

  mpfr		3.0.1
  mpc		0.8.2
  gmp		5.0.5

4.12/rtems-arm builds on FreeBSD.

Ok to update to the 4.11 versions?

Chris