qcacld-3.0: Add "unit_test" IOCTL

Add a unit test IOCTL for components to hook their unit tests into.

Change-Id: I676394771a35263454bc0f6d13174fbb7d957e67
CRs-Fixed: 2274538

Kbuild

@@ -1636,6 +1636,7 @@ cppflags-y +=	-DTRACE_RECORD \
 		-DHDD_TRACE_RECORD
 endif
 endif
+cppflags-$(CONFIG_UNIT_TEST) += -DWLAN_UNIT_TEST
 cppflags-$(CONFIG_WLAN_DEBUG_CRASH_INJECT) += -DCONFIG_WLAN_DEBUG_CRASH_INJECT
 cppflags-$(CONFIG_FEATURE_UNIT_TEST_SUSPEND) += -DWLAN_SUSPEND_RESUME_TEST