perf: Support setting the disassembler style

Add -M option to report/annotate to pass directly to objdump.  This
allows to use -M intel for intel style disassembler syntax, which is
useful for people who are very used to the Intel syntax.

Link: http://lkml.kernel.org/r/1316122302-24306-2-git-send-email-andi@firstfloor.org
[committer note: Add missing Documentation bits, fixup conflicts with 3e6a2a7f

]
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Stephane Eranian <eranian@google.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>