x86: Remove unused config macros from instruction decoder selftest

Remove dummy definitions of CONFIG_X86_64 and CONFIG_X86_32 because
those macros are not used in the instruction decoder anymore.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
LKML-Reference: <20090828221326.8778.70723.stgit@localhost.localdomain>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>