ARM: at91: fix check of valid GPIO for SPI and USB

SPI chip select pins have to be checked by gpio_is_valid().
The USB host overcurrent_pin checking was missing.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
diff --git a/arch/arm/mach-at91/at91sam9261_devices.c b/arch/arm/mach-at91/at91sam9261_devices.c
index 096da87..4db961a 100644
--- a/arch/arm/mach-at91/at91sam9261_devices.c
+++ b/arch/arm/mach-at91/at91sam9261_devices.c
@@ -415,6 +415,9 @@
 		else
 			cs_pin = spi1_standard_cs[devices[i].chip_select];
 
+		if (!gpio_is_valid(cs_pin))
+			continue;
+
 		if (devices[i].bus_num == 0)
 			enable_spi0 = 1;
 		else