net: ipa: pass mem_id to ipa_filter_reset_table()

Pass a memory region ID rather than the address of a memory region
descriptor to ipa_filter_reset_table(), to simplify callers.

We can eliminate the check for a zero region size in this function
because ipa_table_reset_add() checks that before adding anything to
the transaction.

Note that here and in subsequent commits there is no need to check
whether a memory region exists, because we will have already
verified that during initialization.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>