cnss_prealloc: add wrapper APIs if MEM_PRE_ALLOC flag not enabled

Add wrapper api to avoid compilaton failure if
CONFIG_WCNSS_MEM_PRE_ALLOC flag is not enabled.

Change-Id: Ic0625d68f587c79f38f33495b53645f1d7582144
CRs-Fixed: 3492092

Kbuild

@@ -22,6 +22,12 @@ ifeq ($(CONFIG_ICNSS2_QMI),y)
 KBUILD_CPPFLAGS += -DCONFIG_ICNSS2_QMI
 endif
 
+# CONFIG_WCNSS_MEM_PRE_ALLOC should never be "y" here since it
+# can be only compiled as a module from out-of-kernel-tree source.
+ifeq ($(CONFIG_WCNSS_MEM_PRE_ALLOC),m)
+KBUILD_CPPFLAGS += -DCONFIG_WCNSS_MEM_PRE_ALLOC
+endif
+
 # CONFIG_CNSS_PLAT_IPC_QMI_SVC should never be "y" here since it
 # can be only compiled as a module from out-of-kernel-tree source.
 ifeq ($(CONFIG_CNSS_PLAT_IPC_QMI_SVC),m)