block: sed-opal: Removed duplicate OPAL_METHOD_LENGTH definition

The original commit adding the sed-opal library by mistake added two
definitions of OPAL_METHOD_LENGTH, remove one of them.
Signed-off-by: Revanth Rajashekar <revanth.rajashekar@intel.com>
Reviewed-by: Scott Bauer <sbauer@plzdonthack.me>
Reviewed-by: Jon Derrick <jonathan.derrick@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/opal_proto.h

@@ -119,8 +119,6 @@ enum opal_uid {
 	OPAL_UID_HEXFF,
 };
 
-#define OPAL_METHOD_LENGTH 8
-
 /* Enum for indexing the OPALMETHOD array */
 enum opal_method {
 	OPAL_PROPERTIES,