xen+tools: Introduce XEN_SYSCTL_PHYSCAP_vpmu

xen+tools: Introduce XEN_SYSCTL_PHYSCAP_vpmu

Introduce flag XEN_SYSCTL_PHYSCAP_vpmu which
indicates whether the platform supports vPMU
functionality. Modify Xen and tools accordingly.

Take the opportunity and fix XEN_SYSCTL_PHYSCAP_vmtrace
definition in sysctl.h which wrongly use (1 << 6)
instead of (1u << 6).

Signed-off-by: Michal Orzel <michal.orzel@arm.com>
Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>
Acked-by: Nick Rosbrook <rosbrookn@ainfosec.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Acked-by: Ian Jackson <iwj@xenproject.org>
Acked-by: Christian Lindig <christian.lindig@citrix.com>