spi: qup: Allow for compile-testing on !ARM

There seems no reason to restrict testing to ARM, so remove this
constraint to improve test coverage.

Build-tested with allyesconfig on x86.

Signed-off-by: Alex Dewar <alex.dewar90@gmail.com>
Link: https://lore.kernel.org/r/20200904163709.110975-1-alex.dewar90@gmail.com


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