allscenarios-linux.conf: Enable debug uart by default on RaspberryPi

We default to debug-tweaks for our images so let's also have debug
console by default. This will need to tie in with production/development
builds feature in the future.

Signed-off-by: Andrei Gherzan <andrei.gherzan@huawei.com>

meta-ohos-core/conf/distro/allscenarios-linux.conf

@@ -19,3 +19,6 @@ DISTRO_FEATURES_remove = "nfc 3g pcmcia"
 DISTRO_FEATURES_append = "optee"
 
 PREFERRED_VERSION_linux-yocto = "5.10%"
+
+# Default to enabling serial debug console on RaspberryPi
+ENABLE_UART ?= "1"