remoteproc: clean up notification config

Rearrange the config files for remoteproc and IPA to fix their
interdependencies.

First, have CONFIG_QCOM_Q6V5_MSS select QCOM_Q6V5_IPA_NOTIFY so the
notification code is built regardless of whether IPA needs it.

Next, represent QCOM_IPA as being dependent on QCOM_Q6V5_MSS rather
than setting its value to match QCOM_Q6V5_COMMON (which is selected
by QCOM_Q6V5_MSS).

Drop all dependencies from QCOM_Q6V5_IPA_NOTIFY.  The notification
code will be built whenever QCOM_Q6V5_MSS is set, and it has no other
dependencies.

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