haveged: fix build on uclibc

[texierp]

Check for HAVE_GETAUXVAL or HAVE_SYS_AUXV_H before using getauxval to avoid a build failure on uclibc

Fixes:

/bin/bash ../libtool --tag=CC --mode=compile /home/pjtexier/Bureau/buildroot/pj/bootlin-armv5-uclibc/host/bin/arm-linux-gcc -DHAVE_CONFIG_H -I. -I.. -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -Wall -Wextra -Wpedantic -I.. -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -Os -c -o libhavege_la-havege.lo test -f 'havege.c' || echo './'havege.c /bin/bash ../libtool --tag=CC --mode=compile /home/pjtexier/Bureau/buildroot/pj/bootlin-armv5-uclibc/host/bin/arm-linux-gcc -DHAVE_CONFIG_H -I. -I.. -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -Wall -Wextra -Wpedantic -I.. -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -Os -c -o libhavege_la-havegetune.lo test -f 'havegetune.c' || echo './'havegetune.c /bin/bash ../libtool --tag=CC --mode=compile /home/pjtexier/Bureau/buildroot/pj/bootlin-armv5-uclibc/host/bin/arm-linux-gcc -DHAVE_CONFIG_H -I. -I.. -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -Wall -Wextra -Wpedantic -I.. -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -Os -c -o libhavege_la-havegecollect.lo test -f 'havegecollect.c' || echo './'havegecollect.c /bin/bash ../libtool --tag=CC --mode=compile /home/pjtexier/Bureau/buildroot/pj/bootlin-armv5-uclibc/host/bin/arm-linux-gcc -DHAVE_CONFIG_H -I. -I.. -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -Wall -Wextra -Wpedantic -I.. -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -Os -c -o libhavege_la-havegetest.lo test -f 'havegetest.c' || echo './'havegetest.c haveged.c:22:10: erreur fatale: sys/auxv.h : Aucun fichier ou dossier de ce type 22 | #include <sys/auxv.h> | ^~~~ compilation terminée.

Closes: #56

Signed-off-by: Pierre-Jean Texier texier.pj2@gmail.com