Fix Blackfin HARDWARE_PM support

This patch restores the blackfin Hardware Performance Monitor Profiling
support that was killed by the combining of instrumentation menus in
commit 09cadedb.

Since there seems to be no good reason to behave differently from other
architectures, it now automatically selects the hardware performance
counters whenever the profiling is activated.

mach-common/irqpanic.c: pm_overflow calls pm_overflow_handler which is
in oprofile/op_model_bf533.c.  I doubt that setting HARDWARE_PM as "m"
will work at all, since the pm_overflow_handler should be in the core
kernel image because it is called by irqpanic.c.

Therefore, I change HARDWARE_PM from a tristate to a bool.

The whole arch/$(ARCH)/oprofile/ is built depending on CONFIG_OPROFILE. Since
part of the HARDWARE_PM support files sits in this directory, it makes sense to
also depend on OPROFILE, not only PROFILING. Since OPROFILE already depends on
PROFILING, it is correct to only depend on OPROFILE only.

Thanks to Adrian Bunk for finding this bug and providing an initial
patch.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
CC: Adrian Bunk <adrian.bunk@movial.fi>
CC: Randy Dunlap <randy.dunlap@oracle.com>
CC: bryan.wu@analog.com
Acked-by: Robin Getz <rgetz@blackfin.uclinux.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>