regmap: Try to work around Kconfig exploding on HWSPINLOCK

Trying to work with hwspinlock from built in code is painful as it can
be built modular.  Invert the test for REGMAP_HWSPINLOCK for now so we
end up requiring users to depend on HWSPINLOCK=y in order to turn on the
hwspinlock code.

Signed-off-by: Mark Brown <broonie@kernel.org>