ipu_common: Only apply the erratum to MX51

The following erratum :

"ENGcm08316
IPU: Clarification regarding the bypass mode registers setup for
display and camera interfaces"

only applies to mx51, so restrict its usage for this SoC only.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
diff --git a/drivers/video/ipu_common.c b/drivers/video/ipu_common.c
index 9d20c86..4caad4f 100644
--- a/drivers/video/ipu_common.c
+++ b/drivers/video/ipu_common.c
@@ -401,6 +401,7 @@
 int ipu_probe(void)
 {
 	unsigned long ipu_base;
+#if defined CONFIG_MX51
 	u32 temp;
 
 	u32 *reg_hsc_mcd = (u32 *)MIPI_HSC_BASE_ADDR;
@@ -414,6 +415,7 @@
 
 	temp = __raw_readl(reg_hsc_mxt_conf);
 	__raw_writel(temp | 0x10000, reg_hsc_mxt_conf);
+#endif
 
 	ipu_base = IPU_CTRL_BASE_ADDR;
 	ipu_cpmem_base = (u32 *)(ipu_base + IPU_CPMEM_REG_BASE);