Fix typedefs for c bingings

[ectrc]

./external/libhat/include/libhat/c/libhat.h:63:5: error: unknown type name 'scan_alignment'; did you mean 'scan_alignment_t'?
   63 |     scan_alignment      align
      |     ^~~~~~~~~~~~~~
      |     scan_alignment_t
./external/libhat/include/libhat/c/libhat.h:70:5: error: unknown type name 'scan_alignment'; did you mean 'scan_alignment_t'?
   70 |     scan_alignment      align
      |     ^~~~~~~~~~~~~~
      |     scan_alignment_t```

This fixes the C header file bindings for the enum `scan_alignment_t`