arch-arm: Provide default mask for raz/rao helpers

Rather than forcing raz registers to write something like:

.raz(uint64_t(-1))

we provide a shorter version where if
no bitmask is specified we assume the entire register is
raz/rao. This won't be probably used by rao but I
am striving for symmetry and providing a default won't
probably hurt

Change-Id: I309e345fc8336df3a74474f8f9202bf7e2095b41
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Richard Cooper <richard.cooper@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/70559
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

src/arch/arm/regs/misc.hh

@@ -1249,13 +1249,13 @@ namespace ArmISA
             return *this;
         }
         chain
-        raz(uint64_t mask) const
+        raz(uint64_t mask = (uint64_t)-1) const
         {
             entry._raz  = mask;
             return *this;
         }
         chain
-        rao(uint64_t mask) const
+        rao(uint64_t mask = (uint64_t)-1) const
         {
             entry._rao  = mask;
             return *this;