package/xxhash: set XXH_NO_INLINE_HINTS

Set XXH_NO_INLINE_HINTS to marks all internal functions as static,
giving the compiler full control on whether to inline or not. This will
fix the following build failure raised since bump to version 0.8.1 in
commit 5dbdb253:

In file included from xxhash.c:43:
In function 'XXH3_accumulate',
    inlined from 'XXH3_hashLong_internal_loop' at xxhash.h:4390:9,
    inlined from 'XXH3_hashLong_64b_internal' at xxhash.h:4453:5,
    inlined from 'XXH3_hashLong_64b_withSecret' at xxhash.h:4473:12,
    inlined from 'XXH3_64bits_internal' at xxhash.h:4554:12,
    inlined from 'XXH3_64bits_withSecret' at xxhash.h:4570:12:
xxhash.h:4196:1: error: inlining failed in call to 'always_inline' 'XXH3_accumulate_512_scalar': function not considered for inlining
 4196 | XXH3_accumulate_512_scalar(void* XXH_RESTRICT acc,
      | ^~~~~~~~~~~~~~~~~~~~~~~~~~

Fixes:
 - http://autobuild.buildroot.org/results/f2c52238df97cc4c13117d8dc1423235231a094c



Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>