ARM: Enable SG chain

Enable ARM_HAS_SG_CHAIN to allow sg_alloc_table to allocate chain of
scatterlists

Change-Id: I42cf8b2cc337a5be24014508f398cea5560e93f2
Signed-off-by: Varadarajan, Charulatha <charu@ti.com>
Signed-off-by: Atanas (Tony) Zlatinski <zlatinski@gmail.com>

Conflicts:
	arch/arm/Kconfig
sync: allow async waits to be canceled

In order to allow drivers to cleanly handled teardown we need to allow them
to cancel pending async waits.  To do this cleanly, we move allocation of
sync_fence_waiter to the driver calling sync_async_wait().

Change-Id: Ifcd95648be6ec07026d67f810070a4310f099989
Signed-off-by: Erik Gilling <konkers@android.com>
Signed-off-by: Atanas (Tony) Zlatinski <zlatinski@gmail.com>