ctcm: rename READ/WRITE defines to avoid redefinitions

READ/WRITE seems to be a bit too generic for defines in a device
driver. Just rename them to CTCM_READ/CTCM_WRITE to avoid warnings.

Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>