net: ipa: define enumerated types consistently

Consistently define numeric values for enumerated type members using
hexidecimal (rather than decimal) format values.  Align the values
assigned in the same column in each file.

Only assign values where they really matter, for example don't
assign IPA_ENDPOINT_AP_MODEM_TX the value 0.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>