selftests/bpf: Add bpf_get_func_ip test for uprobe inside function

Adding get_func_ip test for uprobe inside function that validates
the get_func_ip helper returns correct probe address value.

Tested-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230807085956.2344866-4-jolsa@kernel.org
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>