xen: arm: extend HSR struct definitions to 64-bit

xen: arm: extend HSR struct definitions to 64-bit

The main change is that the 4-bit register specifiers are extended
to 5 bits by taking in an adjacent SBZP bit.

Also 64-bit has two other properties indicting whether or not the
target register was 64-bit (x<n>) or 32-bit (w<n>) and whether the
instruction has acquire/release semantics.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Tim Deegan <tim@xen.org>