Add a SSYNC() into bfin_serial_dma_tx_chars() to ensure DMA registers are
written with new data otherwise we might miss a byte or two when the
system is under load.  PIO mode is OK though.
Signed-off-by: NGraf Yang <graf.yang@analog.com>
Signed-off-by: NMike Frysinger <vapier@gentoo.org>
Signed-off-by: NBryan Wu <cooloney@kernel.org>
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>