fix: libc: use long for 64-bit types on aarch64

Use long instead of long long on aarch64 for 64_t stdint types.
Introduce inttypes.h to properly support printf format specifiers for
fixed width types for such change.

Change-Id: I0bca594687a996fde0a9702d7a383055b99f10a1
Signed-off-by: Scott Branden <scott.branden@broadcom.com>
diff --git a/plat/rpi/rpi4/rpi4_bl31_setup.c b/plat/rpi/rpi4/rpi4_bl31_setup.c
index 5259859..2fb4d3d 100644
--- a/plat/rpi/rpi4/rpi4_bl31_setup.c
+++ b/plat/rpi/rpi4/rpi4_bl31_setup.c
@@ -5,6 +5,8 @@
  */
 
 #include <assert.h>
+#include <inttypes.h>
+#include <stdint.h>
 
 #include <libfdt.h>
 
@@ -234,7 +236,7 @@
 			fdt_del_mem_rsv(dtb, i);
 			return;
 		}
-		WARN("Keeping unknown /memreserve/ region at 0, size: %lld\n",
+		WARN("Keeping unknown /memreserve/ region at 0, size: %" PRId64 "\n",
 		     size);
 	}
 }