tegra: trimslice: set up serial flash pinmux

When Trimslice is booted from serial flash, the boot ROM does this, so
U-Boot doesn't need to. However, booting from the SD slot for recovery
purposes, the boot ROM does not set up the pinmux for serial flash. Add
code to U-Boot to set this up, so that an SD-based recovery U-Boot image
can upgrade the U-Boot in serial flash.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>

board/compulab/trimslice/trimslice.c

@@ -42,6 +42,11 @@ void gpio_config_uart(void)
 {
 }
 
+void pin_mux_spi(void)
+{
+	funcmux_select(PERIPH_ID_SPI1, FUNCMUX_SPI1_GMC_GMD);
+}
+
 /*
  * Routine: pin_mux_mmc
  * Description: setup the pin muxes/tristate values for the SDMMC(s)