dmaengine: fsldma: Add 64-bit I/O accessors for powerpc64

Otherwise 64-bit PPC builds fail with undefined references
to these accessors.

Cc: Peng Ma <peng.ma@nxp.com>
Cc: Wen He <wen.he_1@nxp.com>
Fixes: 68997fff94afa (" dmaengine: fsldma: Adding macro FSL_DMA_IN/OUT implement for ARM platform")
Signed-off-by: Scott Wood <oss@buserror.net>
Signed-off-by: Vinod Koul <vkoul@kernel.org>