package/azure-iot-sdk-c: remove dummy value of CMAKE_SYSTEM_VERSION

Now CMAKE_SYSTEM_VERSION is properly set in toolchainfile.cmake, it is
no longer necessary to set a dummy value in azure-iot-sdk-c.

Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Cc: Nikita Sobolev <Nikita.Sobolev@synopsys.com>
Cc: André Hentschel <nerv@dawncrow.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

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

@@ -14,11 +14,6 @@ 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)