aesni: declare cpuinfo as int

Change the type of array that stores the cpuinfo
data to int[4] to match the signature of `__cpuinfo`
in `intrin.h` header file.

Signed-off-by: Pengyu Lv <pengyu.lv@arm.com>
diff --git a/library/aesni.c b/library/aesni.c
index 7eb11af..322a255 100644
--- a/library/aesni.c
+++ b/library/aesni.c
@@ -52,7 +52,7 @@
 
     if (!done) {
 #if MBEDTLS_AESNI_HAVE_CODE == 2
-        static unsigned info[4] = { 0, 0, 0, 0 };
+        static int info[4] = { 0, 0, 0, 0 };
 #if defined(_WIN32)
         __cpuid(info, 1);
 #else