cnss2: Add one MSI vector support

Some platforms can't meet the number of MSI interrupt vectors that
wlan driver requires.
Add one MSI interrupt vector support.
If CONFIG_ONE_MSI_VECTOR is not defined, wlan driver fails to load
if reuired MSI vector allocation fails. It is current behavior.
If CONFIG_ONE_MSI_VECTOR is defined, firstly it will allocate multiple
MSI vectors based on MSI config. If MSI vector allocation fails, it
fallbacks to one MSI vector automatically.

Change-Id: I813f7ddf678ecf405e573f3bc72af3e758d1c96d
CRs-Fixed: 3312670

Kbuild

@@ -10,6 +10,10 @@ ifeq ($(CONFIG_CNSS2_QMI),y)
 KBUILD_CPPFLAGS += -DCONFIG_CNSS2_QMI
 endif
 
+ifeq ($(CONFIG_ONE_MSI_VECTOR),y)
+KBUILD_CPPFLAGS += -DCONFIG_ONE_MSI_VECTOR
+endif
+
 ifeq ($(CONFIG_ICNSS2_DEBUG),y)
 KBUILD_CPPFLAGS += -DCONFIG_ICNSS2_DEBUG
 endif