libhugetlbfs: Add i586 to list of compatible host architectures

COMPATIBLE_HOST included support for x86_64 but not for
32-bit x86 architectures - added i586 arch name to cover qemux86, etc.

Signed-off-by: Gary S. Robertson <gary.robertson@linaro.org>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>