modpost: Skip .llvm.call-graph-profile section check

.llvm.call-graph-profile section is added by clang when the kernel is
built with profiles (e.g. -fprofile-sample-use= or -fprofile-use=).
Note that .llvm.call-graph-profile intentionally uses REL relocations
to decrease the object size, for more details see
https://reviews.llvm.org/D104080.

The section contains edge information derived from text sections,
so .llvm.call-graph-profile itself doesn't need more analysis as
the text sections have been analyzed.

This change fixes the kernel build with clang and a sample profile
which currently fails with:

"FATAL: modpost: Please add code to calculate addend for this architecture"

Signed-off-by: Denis Nikitin <denik@chromium.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Fangrui Song <maskray@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>