In kernel 4.14 kmod-bluetooth depends on kmod-crypto-ecdh, add
kmod-crypto-ecdh to LEDE.
Both packages also depend on the kmod-crypto-kpp package. To build this
we have to fix the dependency of CRYPTO_ECDH which has a typo.
This patch is already accepted upstream.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>