libical: Pass TOOLCHAIN_OPTIONS via CFLAGS

libical: Pass TOOLCHAIN_OPTIONS via CFLAGS

This ensures that right sysroot is used during build, otherwise we see
warnings in build about using wrong sysroot and it fails explicitly with
clang

x86_64-yoe-linux-ld: warning: library search path "/usr/lib/gcc/x86_6
4-pc-linux-gnu/11.2.0/../../../../lib64" is unsafe for cross-compilation

x86_64-yoe-linux-ld: cannot find /usr/lib/clang/14.0.0/lib/linux/libc
lang_rt.builtins-x86_64.a: No such file or directory

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>