fmem: interact properly with DMM

On a system with both FMEM and DMM, FMEM must veto
memory hotremove of section(s) FMEM occupies when
in C-state and allow it (after cleaning up metadata)
in T-state (and then change to O-state).

It must also change back to T-state when all sections
FMEM uses have been powered on.

Change-Id: I9766a07305d1e3e2c6ff48e1cbf6933765b751f8
Signed-off-by: Larry Bassel <lbassel@codeaurora.org>
fmem: hotplug notifier should do nothing if fmem is inactive

If fmem discovers it has no memory to manage, it will
stay in an uninitialized state. However, this is
not discovered until long after the hotplug notifier
is set up (which must be in the fmem_init function).

Since fmem has not been initialized, the hotplug notifier
runs and incorrectly causes memory hotremove to fail, as
it bases its decision on uninitialized data.

The fix is for the hotplug notifier to just return
immediately if fmem is in the uninitialized state.

Change-Id: Ia647470d64fe1926be404af419f5f516e6b59c05
Signed-off-by: Larry Bassel <lbassel@codeaurora.org>
FMEM: allocate non-fixed FMEM from memory pool

On platforms whose FMEM is not at a fixed place
and which don't have DMM (such as 7x27a), FMEM
and the EBI memory pool would incorrectly overlap,
and the same memory would be used both as FMEM
and as memory allocated by allocate_contiguous_memory()
at the same time leading to crashes and strange behavior.

There are some unsolved problems related to
allocating FMEM from unstable memory, so we have
decided not to do this any longer. This decision allows
us to simply allocate non-fixed FMEM from the
EBI memory pool (this will prevent FMEM's memory
from being used by another allocator at the same time).
In this case FMEM will appear to "overlap" with
the memory pool, but this now OK as FMEM is allocated
from it.

This also re-enables FMEM on 7x27a and 8625, which
had been disabled due to the above-mentioned bug.

CRs-Fixed: 354254
Change-Id: I8e0bba332c7ddcac1d280de9642078fdfe61bbcc
Signed-off-by: Larry Bassel <lbassel@codeaurora.org>

Conflicts:
	arch/arm/mach-msm/board-8960.c
	arch/arm/mach-msm/board-msm7x27a.c
	arch/arm/mach-msm/memory.c