[ARM] arm32: Add support for VFP virtualization

This patch adds support for VFP virtualization in arm32 port.

The basic idea here is to allow cp10 & cp11 access to normal VCPUs
and monitor access to VFP control registers such as FPSID, FPSCR,
FPEXC, FPINST, FPINST2, MVFR0, and MVFR1.

The patch has been tested on VersatilePB, Realview-EB-MPCore,
Realview-PB-A8, and VExpress-A9 host emulated by QEMU.

More testing will follow on real hardware but for now this is fine.

Signed-off-by: Anup Patel <anup@brainfault.org>