Build failure on OpenBSD

Commit 00ff7863 failed to build on OpenBSD 6.2.

egcc -std=gnu99  -include /home/jenkins/workspace/bind9-master-openbsd62-64/config.h -I/home/jenkins/workspace/bind9-master-openbsd62-64 -I../.. -I./unix/include  -I./pthreads/include  -I./include  -I./include -I/home/jenkins/workspace/bind9-master-openbsd62-64/lib/dns/include  -I../../lib/dns/include -I/usr/include     -DISC_MEM_DEFAULTFILL=1 -DISC_LIST_CHECKINIT=1 -g -O2 -pthread  -fPIC   -W -Wall -Wmissing-prototypes -Wcast-qual -Wwrite-strings -Wformat -Wpointer-arith -fno-strict-aliasing -fno-delete-null-pointer-checks -Wshadow -Werror  -c siphash.c
In file included from siphash.c:36:0:
./include/isc/endian.h:82:2: error: #error Platform not supported
 #error Platform not supported
  ^
*** Error 1 in lib/isc (Makefile:274 'siphash.o')
*** Error 1 in lib (Makefile:89 'subdirs')
*** Error 1 in /home/jenkins/workspace/bind9-master-openbsd62-64 (Makefile:96 'subdirs')

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