ENGR00285441 mxc: mlb: Fix the receive issue of ISOC mode on Sabreauto

ENGR00285441 mxc: mlb: Fix the receive issue of ISOC mode on Sabreauto

This patch fixes the receive issue of MLB ISO mode on Sabreauto side.
During debug, it is found that the Sabreauto can only receive
1/5 packets of MITB sends.The MITB sends out 188 bytes per packet.
The Sabreauto receives 188*5 bytes. It seems that the packet length
on Sabreauto side is 5 times larger than MITB side. After changing
the defautl block number to 1, Sabreauto passes the test.

Signed-off-by: Luwei Zhou <b45643@freescale.com>