firmware: qcom_scm-64: Remove qcom_scm_call_do_smccc

Remove thin wrapper to qcom_scm_call_do_smccc because it doesn't do
enough of anything interesting to dedicate its own function.

Change-Id: Ia726336e4dc14f0a473a86d6c15605a4a020b055
Signed-off-by: Elliot Berman <eberman@codeaurora.org>