selftests: vDSO: parse_vdso: Use UAPI headers instead of libc headers

To allow the usage of parse_vdso.c together with a limited libc like
nolibc, use the kernels own elf.h and auxvec.h headers.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Link: https://lore.kernel.org/all/20250226-parse_vdso-nolibc-v2-12-28e14e031ed8@linutronix.de

Author: t-8ch

tools/testing/selftests/vDSO/Makefile

@@ -19,6 +19,9 @@ LDLIBS += -lgcc_s
 endif
 
 include ../lib.mk
+
+CFLAGS += $(TOOLS_INCLUDES)
+
 $(OUTPUT)/vdso_test_gettimeofday: parse_vdso.c vdso_test_gettimeofday.c
 $(OUTPUT)/vdso_test_getcpu: parse_vdso.c vdso_test_getcpu.c
 $(OUTPUT)/vdso_test_abi: parse_vdso.c vdso_test_abi.c

tools/testing/selftests/vDSO/parse_vdso.c

@@ -19,7 +19,8 @@
 #include <stdint.h>
 #include <string.h>
 #include <limits.h>
-#include <elf.h>
+#include <linux/auxvec.h>
+#include <linux/elf.h>
 
 #include "parse_vdso.h"