net: ipa: get rid of status size constraint

There is a build-time check that the packet status structure is a
multiple of 4 bytes in size.  It's not clear where that constraint
comes from, but the structure defines what hardware provides so its
definition won't change.  Get rid of the check; it adds no value.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>