net: ipa: use version based configuration for SC7180

Rename the SC7180 configuration data file so that its name is
derived from its IPA version.

Update a few other references to the code that talk about the SC7180
rather than just IPA v4.2.

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