meta-ampere: Cleanup for Yocto override syntax change

Run convert-overrides.py meta-ampere and update missing changes as
below:
- Change all _mtjade to :mtjade
- Change all _${PN} to :${PN}

Tested:
1. Check compilation without problem.
2. Check basic functions like switch UART mux, power control.

Signed-off-by: Thang Q. Nguyen <thang@os.amperecomputing.com>
Change-Id: I42038b2a98ed1951d6c770bdf49f5fc440f8163e
diff --git a/meta-ampere/meta-jade/conf/local.conf.sample b/meta-ampere/meta-jade/conf/local.conf.sample
index 54d05d9..914da71 100644
--- a/meta-ampere/meta-jade/conf/local.conf.sample
+++ b/meta-ampere/meta-jade/conf/local.conf.sample
@@ -93,7 +93,7 @@
 # Supported values are i686 and x86_64
 #SDKMACHINE ?= "i686"
 
-SANITY_TESTED_DISTROS_append ?= " *"
+SANITY_TESTED_DISTROS:append ?= " *"
 
 #
 # Extra image configuration defaults