net: ipa: eliminate unneeded struct declarations

net: ipa: eliminate unneeded struct declarations

As definitions in headers have been moved around, some of the
struct and enum declarations found in header files have become
no longer necessary and can be removed.  Remove these unneeded
declarations.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>