console: remove #ifdef CONFIG when it is possible

Remove #ifdef or #ifndef for CONFIG when it is possible to simplify
the console.c code and respect the U-Boot coding rules.

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Simon Glass <sjg@chromium.org>