conf/machine: use a weaker operator to set SERIAL_CONSOLES

We should be able to over-ride this when appropriate in a layer or
local.conf.

Fixes [YOCTO #14109]

Signed-off-by: Anuj Mittal <anuj.mittal@intel.com>

3 files changed, 3 insertions, 3 deletions

diff --git a/conf/machine/intel-core2-32.conf b/conf/machine/intel-core2-32.conf
index 20c98726..384ad1e9 100644
--- a/conf/machine/intel-core2-32.conf
+++ b/conf/machine/intel-core2-32.conf
@@ -27,7 +27,7 @@ XSERVER ?= "${XSERVER_X86_BASE} \
            "
 
 SYSLINUX_OPTS = "serial 0 115200"
-SERIAL_CONSOLES = "115200;ttyS0 115200;ttyS1 115200;ttyPCH0"
+SERIAL_CONSOLES ?= "115200;ttyS0 115200;ttyS1 115200;ttyPCH0"
 APPEND += "rootwait console=ttyS0,115200 console=ttyPCH0,115200 console=tty0"
 
 IMAGE_FSTYPES += "wic"
diff --git a/conf/machine/intel-corei7-64.conf b/conf/machine/intel-corei7-64.conf
index 6164bf3e..20095379 100644
--- a/conf/machine/intel-corei7-64.conf
+++ b/conf/machine/intel-corei7-64.conf
@@ -32,7 +32,7 @@ XSERVER ?= "${XSERVER_X86_BASE} \
            "
 
 SYSLINUX_OPTS = "serial 0 115200"
-SERIAL_CONSOLES = "115200;ttyS0 115200;ttyS1 115200;ttyS2"
+SERIAL_CONSOLES ?= "115200;ttyS0 115200;ttyS1 115200;ttyS2"
 APPEND += "rootwait console=ttyS0,115200 console=tty0"
 
 IMAGE_FSTYPES += "wic"
diff --git a/conf/machine/intel-skylake-64.conf b/conf/machine/intel-skylake-64.conf
index 6ae80a5a..7cc93583 100644
--- a/conf/machine/intel-skylake-64.conf
+++ b/conf/machine/intel-skylake-64.conf
@@ -27,7 +27,7 @@ XSERVER ?= "${XSERVER_X86_BASE} \
            "
 
 SYSLINUX_OPTS = "serial 0 115200"
-SERIAL_CONSOLES = "115200;ttyS0 115200;ttyS1 115200;ttyS2"
+SERIAL_CONSOLES ?= "115200;ttyS0 115200;ttyS1 115200;ttyS2"
 APPEND += "rootwait console=ttyS0,115200 console=tty0"
 
 IMAGE_FSTYPES += "wic"