drivers : usb: fsl: Implement usb Erratum A007798 workaround

Set TXFIFOTHRESH to adjust ddr pipeline delay for successful large
usb writes

Signed-off-by: Nikhil Badola <nikhil.badola@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>
diff --git a/arch/powerpc/include/asm/config_mpc85xx.h b/arch/powerpc/include/asm/config_mpc85xx.h
index 4c1774f..7860b40 100644
--- a/arch/powerpc/include/asm/config_mpc85xx.h
+++ b/arch/powerpc/include/asm/config_mpc85xx.h
@@ -678,6 +678,7 @@
 #define CONFIG_SYS_FSL_ERRATUM_A006379
 #define CONFIG_SYS_FSL_ERRATUM_A007186
 #define CONFIG_SYS_FSL_ERRATUM_A006593
+#define CONFIG_SYS_FSL_ERRATUM_A007798
 #define CONFIG_SYS_CCSRBAR_DEFAULT	0xfe000000
 #define CONFIG_SYS_FSL_SFP_VER_3_0
 #define CONFIG_SYS_FSL_PCI_VER_3_X