build: enable no-parentheses in clang

build: enable no-parentheses in clang

And fix the following errors reported:

traps.c:2014:25: error: equality comparison with extraneous parentheses
      [-Werror,-Wparentheses-equality]
        else if ( (port == RTC_PORT(0)) )
                   ~~~~~^~~~~~~~~~~~~~
traps.c:2014:25: note: remove extraneous parentheses around the comparison to silence this warning
        else if ( (port == RTC_PORT(0)) )
                  ~     ^             ~
traps.c:2014:25: note: use '=' to turn this equality comparison into an assignment
        else if ( (port == RTC_PORT(0)) )
                        ^~
                        =
traps.c:2083:25: error: equality comparison with extraneous parentheses
      [-Werror,-Wparentheses-equality]
        else if ( (port == RTC_PORT(0)) )
                   ~~~~~^~~~~~~~~~~~~~

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>