ppc/8xxx: Remove ddr_pd_cntl register since it doesn't exist

The ddr_pd_cntl isn't defined in any reference manual and thus we wil
remove especially since we set it to 0, which would most likely be its
POR value.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/include/asm-ppc/immap_85xx.h b/include/asm-ppc/immap_85xx.h
index 375d804..e7d412d 100644
--- a/include/asm-ppc/immap_85xx.h
+++ b/include/asm-ppc/immap_85xx.h
@@ -132,7 +132,7 @@
 	char	reg8_1a[8];
 	uint	ddr_zq_cntl;		/* 0x2170 - DDR ZQ calibration control*/
 	uint	ddr_wrlvl_cntl;		/* 0x2174 - DDR write leveling control*/
-	uint	ddr_pd_cntl;		/* 0x2178 - DDR pre-drive conditioning control*/
+	char	reg8_1aa[4];
 	uint	ddr_sr_cntr;		/* 0x217C - DDR self refresh counter */
 	uint	ddr_sdram_rcw_1;	/* 0x2180 - DDR Register Control Words 1 */
 	uint	ddr_sdram_rcw_2;	/* 0x2184 - DDR Register Control Words 2 */