[POWERPC] 4xx: Fix Sequoia MAL0 and EMAC dts entries.

According to PowerPC 440EPx documentation,
MAL0 is comprised of four channels (two transmit and two receive).
Each channel is dedicated to one of two EMAC cores.
This patch fixes Sequoia DTS MAL0 entry and EMAC entries,
assigning correct channel numbers to EMACs.

Signed-off-by: Valentine Barshak <vbarshak@ru.mvista.com>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>