[nrf fromlist] scripts: checkpatch: Allow use of macros in switch-statements

-Adding specialized matching for default label to allow macros being
 used in swich-statements.
 Before this commit, any code that makes use of a macro above default:
 in a switch-statement will cause issues complaining about spaces

 Example:
    switch (a) {
        SOME_MACRO(A)
        default:
             break;
    }

 ... would complain on the colon of the default case, regardless of
 the content of the macro

Signed-off-by: Frank Audun Kvamtrø <frank.kvamtro@nordicsemi.no>
(cherry picked from commit ce50a78375d9241a074f72bbb42c27a476fc73e9)

Author: frkv

scripts/checkpatch.pl

@@ -4723,6 +4723,11 @@ sub process {
 						}
 					}
 
+				# Handle 'default:' explicitly to allow any macros to be used above
+				# the default label in switch-statements
+				} elsif ($sline =~ /^.\s+default:/ && $opv eq ':O') {
+					# Do nothing
+
 				# All the others need spaces both sides.
 				} elsif ($ctx !~ /[EWC]x[CWE]/) {
 					my $ok = 0;