mb/*/*/cmos.default: Decrease debug_level to 'Debug'

Used default console log level is 7 in src/console/Kconfig.
So let cmos.default use the same level as default.

Change-Id: Ia39ee457a8985142f6e7a674532995b11cb52198
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/28006
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Tristan Corrick <tristan@corrick.kiwi>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Martin Roth <martinroth@google.com>

src/mainboard/pcengines/apu1/cmos.default

@@ -1,3 +1,3 @@
 boot_option=Fallback
 multi_core=Enable
-debug_level=Spew
+debug_level=Debug