qcacld-3.0: Remove unused ATH_SUPPORT_SHARED_IRQ macro

The Kbuild currently defines the macro ATH_SUPPORT_SHARED_IRQ. However
this macro is not actually referenced in the driver, so remove it.

Change-Id: I526038c83380da2526c403cba3bedeaa0e347983
CRs-Fixed: 2220912

Kbuild

@@ -312,9 +312,6 @@ ifeq ($(CONFIG_ROME_IF),usb)
 	CONFIG_ATH_11AC_TXCOMPACT := 0
 endif
 
-#Enable OS specific IRQ abstraction
-CONFIG_ATH_SUPPORT_SHARED_IRQ := 1
-
 #Enable message based HIF instead of RAW access in BMI
 ifeq ($(CONFIG_QCA_WIFI_SDIO), 1)
 CONFIG_HIF_MESSAGE_BASED := 0
@@ -2165,11 +2162,6 @@ ifeq ($(CONFIG_ATH_11AC_TXCOMPACT), 1)
 CDEFINES += -DATH_11AC_TXCOMPACT
 endif
 
-#Enable OS specific IRQ abstraction
-ifeq ($(CONFIG_ATH_SUPPORT_SHARED_IRQ), 1)
-CDEFINES += -DATH_SUPPORT_SHARED_IRQ
-endif
-
 #Enable message based HIF instead of RAW access in BMI
 ifeq ($(CONFIG_HIF_MESSAGE_BASED), 1)
 CDEFINES += -DHIF_MESSAGE_BASED