tools: provide a tool to convert a binary file to an include

For testing EFI disk management we need an in-memory image of
a disk.

The tool file2include converts a file to a C include. The file
is separated into strings of 8 bytes. Only the non-zero strings
are written to the include. The output format has been designed
to maintain readability.

 #define EFI_ST_DISK_IMG { 0x00010000, { \
  {0x000001b8, "\x94\x37\x69\xfc\x00\x00\x00\x00"}, /* .7i..... */ \
  {0x000001c0, "\x02\x00\x83\x02\x02\x00\x01\x00"}, /* ........ */ \
  {0x000001c8, "\x00\x00\x7f\x00\x00\x00\x00\x00"}, /* ........ */ \
  {0x000001f8, "\x00\x00\x00\x00\x00\x00\x55\xaa"}, /* ......U. */ \
 ...
  {0x00006000, "\x48\x65\x6c\x6c\x6f\x20\x77\x6f"}, /* Hello wo */ \
  {0x00006008, "\x72\x6c\x64\x21\x0a\x00\x00\x00"}, /* rld!.... */ \
  {0, NULL} } }

As the disk image needed for testing contains mostly zeroes a high
compression ratio can be attained.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Alexander Graf <agraf@suse.de>