lspci: Define PCI_U64_FMT_U format for printing u64

lspci: Define PCI_U64_FMT_U format for printing u64

Windows CRTDLL and MSVCRT runtime system libraries do not support %llu
format string in printf. They support only %I64u format string. Fix this
problem by providing PCI_U64_FMT_U macro in the same way as existing
PCI_U64_FMT_X macro (for %llx).

For C99 systems this PCI_U64_FMT_U macro is defined to C99 PRIu64 constant.

This change fixes printing unsigned decimal 64-bit numbers by lspci on
Window systems independently of used compiler (MinGW or MSVC).