Adding Alpha EV67 support

Maynard,

I follow with the patch to add Alpha EV67 support to operf and remove
all other alpha support.

It compiles fine but does not appear to work properly.  ophelp prints
out:

oprofile: available events for CPU type "Alpha EV67"

See Alpha Architecture Reference Manual
http://download.majix.org/dec/alpha_arch_ref.pdf
For architectures using unit masks, you may be able to specify
unit masks by name.  See 'operf' or 'ocount' man page for more details.

CYCLES: (counter: 0, 1)
	Total cycles (min count: 500)
INSTRUCTIONS: (counter: 0)
	Retired instructions (min count: 500)
BCACHE_MISS: (counter: 1)
	Bcache misses/long probe latency (min count: 500)
MBOX_REPLAY: (counter: 1)
	Mbox replay traps (min count: 500)

which is as expected.  However trying to run operf results in:

$ operf ls
perf_event_open failed with Operation not permitted
Caught runtime_error: Internal Error.  Perf event setup failed.
Error running profiler

I haven't been able to work out why that is occurring.  My own code
to use the kernel performance events works fine, so I would hazard a
guess that operf is setting some flag/parameter when calling the kernel
performance event syscall that I have never tested with.

I am now out of time today to examine this any further.

Cheers
Michael.

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