PPC4XX DMA polarity init fix

[Clear bug fix, hopefully it can go in before 2.6.10]

This patch applies to the kernel 2.6.9 and fixes the initialisation of the DMA channel polarity in the function ppc4xx_init_dma_channel() for the PPC 4XX processor.

===== arch/ppc/syslib/ppc4xx_dma.c 1.8 vs edited =====

@@ -466,7 +466,7 @@
 
 	/* clear all polarity signals and then "or" in new signal levels */
 	polarity &= ~GET_DMA_POLARITY(dmanr);
-	polarity |= p_dma_ch->polarity;
+	polarity |= p_init->polarity;
 #if DCRN_POL > 0
 	mtdcr(DCRN_POL, polarity);
 #endif