libpayload: use PRIu64 type to print u64

The appropriate way to print a u64 variable regardless of the current
architecture is to use the PRI*64 macros.  libpayload is mostly used
in 32 bits but when ported to other projects and compiled in 64 bits
it breaks the compilation.

Change-Id: I479fd701f992701584d77d43c5cd5910f5ab7633
Signed-off-by: Jeremy Compostella <jeremy.compostella@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/45628
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

payloads/libpayload/libc/time.c

@@ -31,11 +31,14 @@
  * General time functions
  */
 
+#define __STDC_FORMAT_MACROS
+
 #include <libpayload-config.h>
 #include <libpayload.h>
 #if CONFIG(LP_ARCH_X86) && CONFIG(LP_NVRAM)
 #include <arch/rdtsc.h>
 #endif
+#include <inttypes.h>
 
 extern u32 cpu_khz;
 
@@ -173,7 +176,7 @@ u64 timer_us(u64 base)
 	if (hz == 0) {
 		hz = timer_hz();
 		if (hz < 1000000) {
-			printf("Timer frequency %lld is too low, "
+			printf("Timer frequency %" PRIu64 " is too low, "
 			       "must be at least 1MHz.\n", hz);
 			halt();
 		}