[Centec arm64] Solve the abnormal console speed of centec-arm64 switch board (#13126)

The console of the centec-arm64 board is ttyAMA0.The current regular expression cannot be correctly parsed.

Signed-off-by: centecqianj <qianj@centec.com>

files/image_config/platform/rc.local

@@ -182,7 +182,7 @@ value_extract() {
 
 program_console_speed()
 {
-    speed=$(cat /proc/cmdline | grep -Eo 'console=ttyS[0-9]+,[0-9]+' | cut -d "," -f2)
+    speed=$(cat /proc/cmdline | grep -Eo 'console=tty(S|AMA)[0-9]+,[0-9]+' | cut -d "," -f2)
     if [ -z "$speed" ]; then
         CONSOLE_SPEED=9600
     else