Add compiler flag to suppress integer to pointer conversions

[abayomi185]

I recently built riscv-gnu-toolchain for cross compilation with gcc 14.2.0 due to build issues. See riscv-collab/riscv-gnu-toolchain#1536

This change was needed to prevent multiple warnings and subsequently a failing build.

I also needed to declare the sysroot directory for bindgen to find the header files required to build wiringx. I am currently declaring this like so:

export BINDGEN_EXTRA_CLANG_ARGS='--sysroot /opt/riscv/sysroot'

[Letronix624]

I appreciate your contribution.