libbpf: move libbpf_sha256() implementation into libbpf_utils.c

Move sha256 implementation out of already large and unwieldy libbpf.c
into libbpf_utils.c where we'll keep reusable helpers.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20251001171326.3883055-5-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>

src/libbpf_internal.h

@@ -722,6 +722,11 @@ static inline bool is_pow_of_2(size_t x)
 	return x && (x & (x - 1)) == 0;
 }
 
+static inline __u32 ror32(__u32 v, int bits)
+{
+	return (v >> bits) | (v << (32 - bits));
+}
+
 #define PROG_LOAD_ATTEMPTS 5
 int sys_bpf_prog_load(union bpf_attr *attr, unsigned int size, int attempts);