Convert CONFIG_VIDEO_SW_CURSOR to Kconfig

This converts the following to Kconfig:
   CONFIG_VIDEO_SW_CURSOR

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
[trini: Re-convert, find all the cases where this is off]
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/nitrogen6s1g_defconfig b/configs/nitrogen6s1g_defconfig
index 10dd5b9..c2985a4 100644
--- a/configs/nitrogen6s1g_defconfig
+++ b/configs/nitrogen6s1g_defconfig
@@ -35,4 +35,5 @@
 CONFIG_G_DNL_MANUFACTURER="Boundary"
 CONFIG_G_DNL_VENDOR_NUM=0x0525
 CONFIG_G_DNL_PRODUCT_NUM=0xa4a5
+# CONFIG_VIDEO_SW_CURSOR is not set
 CONFIG_OF_LIBFDT=y