arm/trusted-firmware-m: package .elf files in PN-dbg

Some platforms install .elf files, so put those into the -dbg package.
This means expanding the buildpaths QA exclusion.

Whilst here, expand the comments for the other INSANE_SKIP statements.

Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Jon Mason <jon.mason@arm.com>

meta-arm/recipes-bsp/trusted-firmware-m/trusted-firmware-m.inc

@@ -106,11 +106,16 @@ do_install() {
 
 FILES:${PN} = "/firmware"
 SYSROOT_DIRS += "/firmware"
+FILES:${PN}-dbg = "/firmware/*.elf"
 
 addtask deploy after do_install
 do_deploy() {
     cp -rf ${D}/firmware/* ${DEPLOYDIR}/
 }
 
-# Build paths are currently embedded
+# Build paths are currently embedded because it's impossible to pass -fdebug-prefix-map
 INSANE_SKIP:${PN} += "buildpaths"
+INSANE_SKIP:${PN}-dbg += "buildpaths"
+# Target binaries will be 32-bit Arm
+INSANE_SKIP:${PN} += "arch"
+INSANE_SKIP:${PN}-dbg += "arch"