linuxloader: add -armhf on arm only for TARGET_FPU 'hard'

There are two types of soft FPU options for arm, soft and softfp, and if
using the latter the wrong dynamic loader will be used.

E.g. go will link against ld-linux-armhf.so.3, but libc6 will only ship
a ld-linux.so.3, so go programs will fail to start.

Fix this by instead checking for TARGET_FPU being 'hard' and then
applying the suffix.

Signed-off-by: Jonas Gorski <jonas.gorski@bisdn.de>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>