[POWERPC] 4xx: Fix Bamboo MAL0 dts entry.

According to PowerPC 440EP documentation,
MAL0 consists of 6 channels (4 transmit channels and 2 receive channels)
This patch fixes Bamboo DTS MAL0 "num-rx-chans" entry.
Signed-off-by: Valentine Barshak <vbarshak@ru.mvista.com>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>

arch/powerpc/boot/dts/bamboo.dts

@@ -94,7 +94,7 @@
 			compatible = "ibm,mcmal-440ep", "ibm,mcmal-440gp", "ibm,mcmal";
 			dcr-reg = <180 62>;
 			num-tx-chans = <4>;
-			num-rx-chans = <4>;
+			num-rx-chans = <2>;
 			interrupt-parent = <&MAL0>;
 			interrupts = <0 1 2 3 4>;
 			#interrupt-cells = <1>;