Add more bits for the XSAVE features from CPUID 0xd, sub-function 1
%eax report.

Print the XSAVE features 0xd/1 in the boot banner. The printcpuinfo()
is executed late enough so that XSAVE is already enabled.

There is no known to me off the shelf hardware that implements any
feature bits except XSAVEOPT, the list is taken from SDM rev. 50. The
banner printing will allow us to note the hardware arrival.

Sponsored by: The FreeBSD Foundation
MFC after: 1 week