package/azure-iot-sdk-c: bump to version 2018-12-13

Bump azure-iot-sdk-c to 2018-12-13 release.

We need to specify a value for CMAKE_SYSTEM_VERSION, because the
azure-iot-sdk-c build system is doing a test on this value, and CMake
doesn't internally define it when cross-compiling (see
https://cmake.org/cmake/help/v3.4/variable/CMAKE_SYSTEM_VERSION.html).

Signed-off-by: Nikita Sobolev <Nikita.Sobolev@synopsys.com>
[Thomas: drop patch, pass dummy CMAKE_SYSTEM_VERSION instead.]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/azure-iot-sdk-c/azure-iot-sdk-c.mk

@@ -4,7 +4,7 @@
 #
 ################################################################################
 
-AZURE_IOT_SDK_C_VERSION = 2018-03-16
+AZURE_IOT_SDK_C_VERSION = 2018-12-13
 AZURE_IOT_SDK_C_SITE = https://github.com/Azure/azure-iot-sdk-c
 AZURE_IOT_SDK_C_SITE_METHOD = git
 AZURE_IOT_SDK_C_GIT_SUBMODULES = YES
@@ -14,6 +14,11 @@ AZURE_IOT_SDK_C_INSTALL_STAGING = YES
 AZURE_IOT_SDK_C_DEPENDENCIES = libxml2 openssl libcurl util-linux
 AZURE_IOT_SDK_C_CONF_OPTS = -Dskip_samples=ON
 
+# When cross-compiling, CMake doesn't internally pass any
+# CMAKE_SYSTEM_VERSION, so pass a dummy version to make the c-utility
+# WIN32 test happy.
+AZURE_IOT_SDK_C_CONF_OPTS += -DCMAKE_SYSTEM_VERSION=1.0
+
 # The project only supports building one kind of library.
 # Further the install target installs the wrong files, so we do it here:
 ifeq ($(BR2_STATIC_LIBS),y)