lib: x86: Use portable format macros for uint32_t

Compilation of the files fails on ARCH=i386 with i686-elf gcc because
they use "%x" or "%d" format specifier that does not match the actual
size of uint32_t:

x86/s3.c: In function ‘main’:
x86/s3.c:53:35: error: format ‘%x’ expects argument of type ‘unsigned int’, but argument 2 has type ‘u32’ {aka ‘long unsigned int’}
[-Werror=format=]
   53 |  printf("PM1a event registers at %x\n", fadt->pm1a_evt_blk);
      |                                  ~^     ~~~~~~~~~~~~~~~~~~
      |                                   |         |
      |                                   |         u32 {aka long unsigned int}
      |                                   unsigned int
      |                                  %lx

Use PRIx32 instead of "x" and PRId32 instead of "d" to take into account
u32_long case.

Cc: Alex Bennée <alex.bennee@linaro.org>
Cc: Andrew Jones <drjones@redhat.com>
Cc: Cameron Esfahani <dirty@apple.com>
Signed-off-by: Roman Bolshakov <r.bolshakov@yadro.com>
Message-Id: <20200901085056.33391-6-r.bolshakov@yadro.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>