x86emul: use msr definitions in msr-index.h

x86emul: use msr definitions in msr-index.h

Change the names used in code according to numeric values. Remove the
now unused macros in x86_emualte.c and fix indentation. This in turns
requires including msr-index.h  and removing duplicates in userspace
x86_emulate.c in userspace harness program.

No functional change.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>