qcacld-3.0: Define WLAN_HOST_ARCH_ARM in Kbuild

Some features depend on whether the host architecture is ARM or not.
Define WLAN_HOST_ARCH_ARM so these features are included correctly.

Change-Id: Ibd19858edf5c24841fc31d342ab448e635ae0d68
CRs-Fixed: 2215586

Kbuild

@@ -2588,6 +2588,13 @@ ifdef WLAN_HDD_ADAPTER_MAGIC
 CDEFINES += -DWLAN_HDD_ADAPTER_MAGIC=$(WLAN_HDD_ADAPTER_MAGIC)
 endif
 
+# Determine if we are building against an arm architecture host
+ifeq ($(findstring arm, $(ARCH)),)
+	CDEFINES += -DWLAN_HOST_ARCH_ARM=0
+else
+	CDEFINES += -DWLAN_HOST_ARCH_ARM=1
+endif
+
 # inject some build related information
 ifeq ($(CONFIG_BUILD_TAG), y)
 CLD_CHECKOUT = $(shell cd "$(WLAN_ROOT)" && \