ncr5380: Remove REAL_DMA and REAL_DMA_POLL macros

For the NCR5380.c core driver, these macros are never used.
If REAL_DMA were to be defined, compilation would fail.

For the atari_NCR5380.c core driver, REAL_DMA is always defined.

Hence these macros are pointless.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>