binutils: exclude binutils versions that don't support EABIhf

The ARM EABIhf support was introduced in Binutils 2.22, so earlier
versions should not be selected when EABIhf is used.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>