video: Convert CONFIG_VIDEO_LOGO to Kconfig

This converts the following to Kconfig:
   CONFIG_VIDEO_LOGO

Note that this option depends on CONFIG_DM_VIDEO now, since cfb_console is
deprecated. The only relevant code is now in splash.c

Drop the check for DM_VIDEO in that file.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/configs/gwventana_emmc_defconfig b/configs/gwventana_emmc_defconfig
index 67a22f5..dd85723 100644
--- a/configs/gwventana_emmc_defconfig
+++ b/configs/gwventana_emmc_defconfig
@@ -140,6 +140,7 @@
 CONFIG_USB_ETHER=y
 CONFIG_USB_ETH_CDC=y
 CONFIG_DM_VIDEO=y
+CONFIG_VIDEO_LOGO=y
 # CONFIG_BACKLIGHT is not set
 # CONFIG_CMD_VIDCONSOLE is not set
 # CONFIG_VIDEO_BPP8 is not set