firmware: qcom_scm: Fix compilation with QCOM_SCM config

Fix the compilation issue caused by QCOM_SCM and QCOM_SCM_QCPE
config flags by removing the redundancy of having a separate
qcom_scm-smc_qcpe.c file for adding QCPE support.

Change-Id: Idaa998565464ebeef16990afdc2de2c1a3094a5e
Signed-off-by: katamoni sai abhilash <katamoni@codeaurora.org>