powerpc/83xx: Do not configure or probe disabled FSL DR USB controllers

On MPC837X CPUs Dual-Role USB isn't always available (for example DR
USB pins can be muxed away to eSDHC).

U-Boot adds status = "disabled" property into the DR USB nodes to
indicate that we must not try to configure or probe Dual-Role USB,
otherwise we'll break eSDHC support on targets with MPC837X CPUs.
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

arch/powerpc/platforms/83xx/usb.c

@@ -14,6 +14,7 @@
 #include <linux/stddef.h>
 #include <linux/kernel.h>
 #include <linux/errno.h>
+#include <linux/of.h>
 
 #include <asm/io.h>
 #include <asm/prom.h>
@@ -210,7 +211,7 @@ int mpc837x_usb_cfg(void)
 	int ret = 0;
 
 	np = of_find_compatible_node(NULL, NULL, "fsl-usb2-dr");
-	if (!np)
+	if (!np || !of_device_is_available(np))
 		return -ENODEV;
 	prop = of_get_property(np, "phy_type", NULL);
 

arch/powerpc/sysdev/fsl_soc.c

@@ -22,6 +22,7 @@
 #include <linux/module.h>
 #include <linux/device.h>
 #include <linux/platform_device.h>
+#include <linux/of.h>
 #include <linux/of_platform.h>
 #include <linux/phy.h>
 #include <linux/phy_fixed.h>
@@ -328,6 +329,9 @@ static int __init fsl_usb_of_init(void)
 		struct fsl_usb2_platform_data usb_data;
 		const unsigned char *prop = NULL;
 
+		if (!of_device_is_available(np))
+			continue;
+
 		memset(&r, 0, sizeof(r));
 		memset(&usb_data, 0, sizeof(usb_data));