powerpc/85xx: Fix pin muxing for second USB controller

On P1022/P1013 second USB controller is muxed with second
Ethernet controller. The current code to enable second USB
fails to properly clear pinmux bits used by ethernet. As a
result, Linux freezes when this controller is used. This
patch fixes the problem.
Signed-off-by: NFelix Radensky <felix@embedded-sol.com>
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>

arch/powerpc/include/asm/immap_85xx.h

@@ -2017,7 +2017,7 @@ typedef struct ccsr_gur {
 #define MPC85xx_PMUXCR2_PLL_LKDT_EXPOSE		0x00001000
 #endif
 #if defined(CONFIG_P1013) || defined(CONFIG_P1022)
-#define MPC85xx_PMUXCR2_ETSECUSB_MASK	0x001f1000
+#define MPC85xx_PMUXCR2_ETSECUSB_MASK	0x001f8000
 #define MPC85xx_PMUXCR2_USB		0x00150000
 #endif
 	u8	res6[8];