ntp: does not work with libressl

Fixes #10556

The --with-crypto handling in ntp only works with libopenssl, not with
libressl, where it ends up with compilation issues like:

ntp_control.c:(.text+0x64): undefined reference to `EVP_MD_CTX_new'
ntp_control.c:(.text+0x10c): undefined reference to `EVP_MD_CTX_free'
libntpd.a(ntp_crypto.o): In function `bighash':
ntp_crypto.c:(.text+0x2e8): undefined reference to `EVP_MD_CTX_new'
ntp_crypto.c:(.text+0x328): undefined reference to `EVP_MD_CTX_free'
libntpd.a(ntp_crypto.o): In function `crypto_verify':
ntp_crypto.c:(.text+0x6cc): undefined reference to `EVP_MD_CTX_new'
ntp_crypto.c:(.text+0x710): undefined reference to `EVP_MD_CTX_free'
ntp_crypto.c:(.text+0x72c): undefined reference to `EVP_MD_CTX_free'

So ensure we only pass --with-crypto when libopenssl is used.

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
(cherry picked from commit 522111f81c7d535f4f362ad4a15d141d0eb39ec5)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/ntp/ntp.mk

@@ -23,7 +23,7 @@ NTP_CONF_OPTS = \
 # 0003-ntpq-fpic.patch
 NTP_AUTORECONF = YES
 
-ifeq ($(BR2_PACKAGE_OPENSSL),y)
+ifeq ($(BR2_PACKAGE_LIBOPENSSL),y)
 NTP_CONF_OPTS += --with-crypto
 NTP_DEPENDENCIES += openssl
 else