computeinfo: add CL_DEVICE_HALF_FP_CONFIG (#2001)

The computeinfo test already checks that the cl_khr_fp16 extension is
available before querying `CL_DEVICE_HALF_FP_CONFIG`, but never actually
made the `CL_DEVICE_HALF_FP_CONFIG` query.

Signed-off-by: Sven van Haastregt <sven.vanhaastregt@arm.com>

test_conformance/computeinfo/main.cpp

@@ -188,6 +188,7 @@ config_info config_infos[] = {
  CONFIG_INFO(2, 0, CL_DEVICE_IMAGE_BASE_ADDRESS_ALIGNMENT, cl_uint),
 
  CONFIG_INFO(1, 1, CL_DEVICE_MEM_BASE_ADDR_ALIGN, cl_uint),
+ CONFIG_INFO(1, 1, CL_DEVICE_HALF_FP_CONFIG, cl_device_fp_config),
  CONFIG_INFO(1, 1, CL_DEVICE_SINGLE_FP_CONFIG, cl_device_fp_config),
  CONFIG_INFO(1, 1, CL_DEVICE_DOUBLE_FP_CONFIG, cl_device_fp_config),
  CONFIG_INFO(1, 1, CL_DEVICE_GLOBAL_MEM_CACHE_TYPE,