include: Install linux/if_alg.h for user-space crypto API

Signed-off-by: Miloslav Trmač <mitr@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

include/linux/Kbuild

@@ -154,6 +154,7 @@ header-y += icmpv6.h
 header-y += if.h
 header-y += if_addr.h
 header-y += if_addrlabel.h
+header-y += if_alg.h
 header-y += if_arcnet.h
 header-y += if_arp.h
 header-y += if_bonding.h