configs: atmel: ensure EABIhf is selected for sama5d*

The recent changes in Config.in.arm regarding the VFP selection broke the
atmel_sama5d* defconfigs. Ensure EABIhf is selected as all the sama5 have a
vfp.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>