dhcp: Fix config files paths

The built dhcp binaries and the installed startup scripts used configuration
files under /etc/, but the configuration files were installed under /etc/dhcp/.
Fix everything to have configuration files under /etc/dhcp/.

Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/dhcp/S80dhcp-server

@@ -9,7 +9,7 @@ INTERFACES=""
 
 # Sanity checks
 test -f /usr/sbin/dhcpd || exit 0
-test -f /etc/dhcpd.conf || exit 0
+test -f /etc/dhcp/dhcpd.conf || exit 0
 test -n "$INTERFACES" || exit 0
 
 case "$1" in

package/dhcp/dhcp.mk

@@ -9,7 +9,10 @@ DHCP_SITE = http://ftp.isc.org/isc/dhcp/$(DHCP_VERSION)
 DHCP_INSTALL_STAGING = YES
 DHCP_LICENSE = ISC
 DHCP_LICENSE_FILES = LICENSE
-DHCP_CONF_ENV = ac_cv_file__dev_random=yes
+DHCP_CONF_ENV = \
+	CPPFLAGS='-D_PATH_DHCPD_CONF=\"/etc/dhcp/dhcpd.conf\" \
+		-D_PATH_DHCLIENT_CONF=\"/etc/dhcp/dhclient.conf\"' \
+	ac_cv_file__dev_random=yes
 DHCP_CONF_OPT = \
 	--localstatedir=/var/lib/dhcp \
 	--with-srv-lease-file=/var/lib/dhcp/dhcpd.leases \