net: ipa: rename interconnect settings

Use "bandwidth" rather than "rate" in describing the average and
peak values to use for IPA interconnects.  They should have been
named that way to begin with.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
(cherry picked from commit bf52e27b)