cros_ec: Disable the Chrome OS EC in SPL

This is not used in SPL so don't allow it to be built there, even if I2C
is enabled in SPL.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index fc8eb6f..cd4846b 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -10,11 +10,13 @@
 obj-$(CONFIG_ALTERA_SYSID) += altera_sysid.o
 obj-$(CONFIG_DS4510)  += ds4510.o
 obj-$(CONFIG_CBMEM_CONSOLE) += cbmem_console.o
+ifndef CONFIG_SPL_BUILD
 obj-$(CONFIG_CROS_EC) += cros_ec.o
 obj-$(CONFIG_CROS_EC_LPC) += cros_ec_lpc.o
 obj-$(CONFIG_CROS_EC_I2C) += cros_ec_i2c.o
 obj-$(CONFIG_CROS_EC_SANDBOX) += cros_ec_sandbox.o
 obj-$(CONFIG_CROS_EC_SPI) += cros_ec_spi.o
+endif
 obj-$(CONFIG_FSL_DEBUG_SERVER) += fsl_debug_server.o
 obj-$(CONFIG_FSL_IIM) += fsl_iim.o
 obj-$(CONFIG_GPIO_LED) += gpio_led.o