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/pico-imx7d_defconfig b/configs/pico-imx7d_defconfig
index 8e7e10e..ed20aea 100644
--- a/configs/pico-imx7d_defconfig
+++ b/configs/pico-imx7d_defconfig
@@ -85,6 +85,7 @@
 CONFIG_USB_GADGET_PRODUCT_NUM=0xa4a5
 CONFIG_CI_UDC=y
 CONFIG_DM_VIDEO=y
+CONFIG_VIDEO_LOGO=y
 CONFIG_SYS_WHITE_ON_BLACK=y
 CONFIG_VIDEO_MXS=y
 CONFIG_SPLASH_SCREEN=y