qcacld-3.0: Add compilation flag of CONFIG_AR6320_SUPPORT

In Kernel 5.4/4.19, CNSS2 will check if the current enumerated
device id matches with the device id in pld_pcie_id_table[]
by calling cnss_wlan_register_driver(). When using ROME, the
enumerated id is 0x3e, but it is not defined in pld_pcie_id_table
if CONFIG_AR6320_SUPPORT is not set. To avoid this issue, add
compilation flag for CONFIG_AR6320_SUPPORT, then set it in your
qcacld build env for ROME chip.

Change-Id: I7b0fee679923402c43487299e31696d847552335
CRs-Fixed: 2906988

Kbuild

@@ -3080,6 +3080,8 @@ cppflags-y += -DCONFIG_SDIO_TRANSFER_MAILBOX
 endif
 endif
 
+cppflags-$(CONFIG_AR6320_SUPPORT) += -DCONFIG_AR6320_SUPPORT
+
 ifeq ($(CONFIG_WLAN_FEATURE_DSRC), y)
 cppflags-y += -DWLAN_FEATURE_DSRC