tools headers UAPI: Sync kvm.h headers with the kernel sources

To pick the changes in:

  d9a47eda ("KVM: PPC: Book3S HV: Introduce new capability for 2nd DAWR")
  8d4e7e80 ("KVM: x86: declare Xen HVM shared info capability and add test case")
  40da8ccd ("KVM: x86/xen: Add event channel interrupt vector upcall")

These new IOCTLs are now supported on 'perf trace':

  $ tools/perf/trace/beauty/kvm_ioctl.sh > before
  $ cp include/uapi/linux/kvm.h tools/include/uapi/linux/kvm.h
  $ tools/perf/trace/beauty/kvm_ioctl.sh > after
  $ diff -u before after
  --- before	2021-02-23 09:55:46.229058308 -0300
  +++ after	2021-02-23 09:55:57.509308058 -0300
  @@ -91,6 +91,10 @@
   	[0xc1] = "GET_SUPPORTED_HV_CPUID",
   	[0xc6] = "X86_SET_MSR_FILTER",
   	[0xc7] = "RESET_DIRTY_RINGS",
  +	[0xc8] = "XEN_HVM_GET_ATTR",
  +	[0xc9] = "XEN_HVM_SET_ATTR",
  +	[0xca] = "XEN_VCPU_GET_ATTR",
  +	[0xcb] = "XEN_VCPU_SET_ATTR",
   	[0xe0] = "CREATE_DEVICE",
   	[0xe1] = "SET_DEVICE_ATTR",
   	[0xe2] = "GET_DEVICE_ATTR",
  $

Addressing this perf build warning:
  Warning: Kernel ABI header at 'tools/include/uapi/linux/kvm.h' differs from latest version at 'include/uapi/linux/kvm.h'
  diff -u tools/include/uapi/linux/kvm.h include/uapi/linux/kvm.h

Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Paul Mackerras <paulus@ozlabs.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>