ac/rgp: add helper function to write rgp elf oject

ac/rgp: add helper function to write rgp elf oject

This patch adds helper function ac_rgp_write_elf_object() which
creates elf object from struct rgp_code_object_record. The elf
object is written to given output rgp profile file.

v2: for newly added files, change copyright year from 2020 to 2021
v3: fix 32bit compilation failure

Signed-off-by: Yogesh Mohan Marimuthu <yogesh.mohanmarimuthu@amd.com>
Reviewed-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Acked-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8609>