Merge branch 'net-ipa-remove-a-build-dependency'

Alex Elder says:

====================
net: ipa: remove a build dependency

Unlike the original (temporary) IPA notification mechanism, the
generic remoteproc SSR notification code does not require the IPA
driver to maintain a pointer to the modem subsystem remoteproc
structure.

The IPA driver was converted to use the newer SSR notifiers, but the
specification and use of a phandle for the modem subsystem was never
removed.

This series removes the lookup of the remoteproc pointer, and that
removes the need for the modem DT property.  It also removes the
reference to the "modem-remoteproc" property from the DT binding,
and from the DT files that specified them.
====================

Link: https://lore.kernel.org/r/20210120212606.12556-1-elder@linaro.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>