hackrf: new package

This patch adds hackrf/host tools for HackRF, a low cost, open source
Software Defined Radio platform.

Sources of host tools are available on GitHub here:
https://github.com/mossmann/hackrf/tree/master/host

Signed-off-by: Jason Pruitt <jrspruitt@gmail.com>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
[Arnout:
 - Rename package to hackrf to match upstream name;
 - Reorder dependencies and remove empty line (check-package);
 - Use only sha256 hash;
 - Add hash for license file;
 - Bump to 2018.01.1;
 - Use uploaded tarball rather than github-generated one;
 - Fix dependencies of comment (|| instead of &&)
 - Add UDEV_RULES_GROUP=plugdev in case the build host doesn't have
   this group;
 - Add patch fixing build without C++ compiler.
]
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/hackrf/hackrf.mk

@@ -0,0 +1,26 @@
+################################################################################
+#
+# hackrf
+#
+################################################################################
+
+HACKRF_VERSION = 2018.01.1
+HACKRF_SITE = https://github.com/mossmann/hackrf/releases/download/v$(HACKRF_VERSION)
+HACKRF_SOURCE = hackrf-$(HACKRF_VERSION).tar.xz
+HACKRF_LICENSE = GPL-2.0+ BSD-3c
+HACKRF_LICENSE_FILES = COPYING
+HACKRF_DEPENDENCIES = fftw libusb
+HACKRF_SUBDIR = host
+HACKRF_INSTALL_STAGING = YES
+
+HACKRF_CONF_OPTS += -DBUILD_HACKRF_TOOLS=ON
+
+ifeq ($(BR2_PACKAGE_HAS_UDEV),y)
+HACKRF_CONF_OPTS += \
+	-DINSTALL_UDEV_RULES=ON \
+	-DUDEV_RULES_GROUP=plugdev
+else
+HACKRF_CONF_OPTS += -DINSTALL_UDEV_RULES=OFF
+endif
+
+$(eval $(cmake-package))