Avoid:
u-boot-1_2024.01-r0 do_package_qa: QA Issue: File /boot/u-boot-qemuriscv64-2024.01-r0.elf in package u-boot contains reference to TMPDIR [buildpaths]
by ensuring the compiler has the prefix mapping options passed in to it
to correctly remap the source paths and avoid the warning.
(From OE-Core rev: 85c6b06da641fdaf09f2cfe7066e0cf1185c7969)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>