ion: Switch map/unmap dma api to sg_tables

Switch these api's from scatterlists to sg_tables

Signed-off-by: Rebecca Schultz Zavin <rebecca@android.com>
[jstultz: modified patch to apply to staging directory]
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --cc drivers/staging/android/ion/ion.c
Simple merge

diff --cc drivers/staging/android/ion/ion.h
Simple merge

diff --cc drivers/staging/android/ion/ion_priv.h
Simple merge

diff --cc drivers/staging/android/ion/ion_system_heap.c
Simple merge