Revert "build: Remove unused qcom CFLAG"

This reverts commit bb25a9c6c4d7572679484959f339d7d3454f2a6e.
Revert "build: Add QCOM flags to Clang CFLAGS"

This reverts commit b25832bc6798296ccc7b1ea5f0ca14d2bc4a6052.
Revert "build: Clean up QCOM flag definitions"

This reverts commit 4fb3547bf5ae53c73d278c7f42513ba66fdae1d0.