Pull up the following, requested by msaitoh in ticket #1494:

sys/arch/x86/include/specialreg.h 1.146, 1.151-1.154, 1.156 via patch
usr.sbin/cpuctl/arch/i386.c 1.105-1.107 via patch

- Add definitions of AMD's CPUID Fn8000_0008 %ebx.
- Add definitions of AMD's CPUID Fn8000_001f Encrypted Memory features.
- Add definition of AMD's CPUID Fn8000_000a %edx bit 11 "GMET".
- Define CPUID_AMD_SVM_PFThreshold correctly.
- Modify comment a bit for consistency.
- Call cpu_dcp_cacheinfo() only when the cpuid Topology Extension flag
  is set on AMD processor.
- Fix typos.

(martin)