ARM: tegra: Fix can2 on Tegra30 Apalis

CAN2 currently fails on probe as follows:

mcp251x spi1.1: Probe failed, err=19

Fix this by enabling input on pin mux of resp. SPI4 pins.
Signed-off-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Signed-off-by: Marcel Ziswiler <marcel@ziswiler.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

arch/arm/boot/dts/tegra30-apalis.dtsi

@@ -118,6 +118,7 @@ gmi_a16_pj7 {
 				nvidia,function = "spi4";
 				nvidia,pull = <TEGRA_PIN_PULL_NONE>;
 				nvidia,tristate = <TEGRA_PIN_DISABLE>;
+				nvidia,enable-input = <TEGRA_PIN_ENABLE>;
 			};
 			/* CAN_INT2 */
 			spi2_cs2_n_pw3 {