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/tools/buildman/README b/tools/buildman/README
index 6007947..ec2d4e7 100644
--- a/tools/buildman/README
+++ b/tools/buildman/README
@@ -1017,7 +1017,7 @@
     + u-boot.cfg: CONFIG_SPL_ENV_SUPPORT=1 CONFIG_SPL_NET_SUPPORT=1
     + u-boot-spl.cfg: CONFIG_SPL_MMC_SUPPORT=1 CONFIG_SPL_NAND_SUPPORT=1
     + all: CONFIG_SPL_ENV_SUPPORT=1 CONFIG_SPL_MMC_SUPPORT=1 CONFIG_SPL_NAND_SUPPORT=1 CONFIG_SPL_NET_SUPPORT=1
-    44: Convert CONFIG_SPL_USB_HOST_SUPPORT to Kconfig
+    44: Convert CONFIG_SPL_USB_HOST to Kconfig
     ...
 
 This shows that commit 44 enabled three new options for the board