log: fix typo LOGL_EFI

According to the documentation the EFI log category is called LOGC_EFI.
All other categories start with LOGC_. So let's fix it.

Fixes: 1973b381 ("log: add category LOGC_EFI")
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Alexander Graf <agraf@suse.de>