Rename SPL_USB_HOST_SUPPORT to SPL_USB_HOST

Rename this option so that CONFIG_IS_ENABLED can be used with it.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/configs/colibri_imx6_defconfig b/configs/colibri_imx6_defconfig
index 23cdea9..8fbeaee 100644
--- a/configs/colibri_imx6_defconfig
+++ b/configs/colibri_imx6_defconfig
@@ -28,7 +28,7 @@
 CONFIG_MISC_INIT_R=y
 CONFIG_SPL_DMA=y
 CONFIG_SPL_I2C_SUPPORT=y
-CONFIG_SPL_USB_HOST_SUPPORT=y
+CONFIG_SPL_USB_HOST=y
 CONFIG_SPL_USB_GADGET=y
 CONFIG_SPL_USB_SDP_SUPPORT=y
 CONFIG_SYS_PROMPT="Colibri iMX6 # "