Enable CONFIG_VFP again which was disabled during the 4.9 -> 4.14 bump.
Boot tested both 32 and 64 bit subtargets using initramfs images with the
qemu-system-arm and qemu-system-aarch64 emulators.
Fixes: aa100b66f2 ("armvirt: bump to v4.14")
Signed-off-by: Jo-Philipp Wich <jo@mein.io>