Add some standard headers external code might need

Add some standard headers external code might need

inttypes.h defines format specifiers for printf which work with data types of
particular sizes. stdlib.h is currently just a passthrough to malloc.h which
has declarations of the various *alloc functions.

Add the required #define to common.h so that these printf format specifiers
will be made available.

Signed-off-by: Gabe Black <[email protected]>
Reviewed-by: Gabe Black <[email protected]>
Tested-by: Gabe Black <[email protected]>
Reviewed-by: Bill Richardson <[email protected]>
Signed-off-by: Simon Glass <[email protected]>
(Replaced with a GPL version from glibc)