kernel-yocto: allow early exit to configuration audit

With the ability to tag raw configuration fragments as "hardware",
there is a chance that badly behaved fragments throw warnings or
cause other issues that are not applicable during development (or
you understand the risk).

Allow kernel configuration audit to be skipped if KMETA_AUDIT is
not set (by default it is), to provide a flag for control over
auditing.

(From OE-Core rev: a39a1f7cf78ad1ca07438bce634a47e970f25047)

Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes-recipe/kernel-yocto.bbclass

@@ -568,6 +568,11 @@ python do_config_analysis() {
 python do_kernel_configcheck() {
     import re, string, sys, subprocess
 
+    audit_flag = d.getVar( "KMETA_AUDIT" )
+    if not audit_flag:
+       bb.note( "kernel config audit disabled, skipping .." )
+       return
+
     s = d.getVar('S')
 
     # if KMETA isn't set globally by a recipe using this routine, use kgit to