firmware: qcom_scm-32: Add funcnum IDs

Add SCM_LEGACY_FNID macro to qcom_scm-32.

Tested-by: Brian Masney <masneyb@onstation.org> # arm32
Tested-by: Stephan Gerhold <stephan@gerhold.net>
Signed-off-by: Elliot Berman <eberman@codeaurora.org>
Link: https://lore.kernel.org/r/1578431066-19600-11-git-send-email-eberman@codeaurora.org


Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>