qcacmn: Remove DP_INTR_POLL flag

Remove DP_INTR_POLL FLAG as polling is now handled runtime using
hif_is_polled_mode_enabled. This is needed as 8074 works on interrupts
whereas 6290 is still working on polling mode

Change-Id: I0e7fdc338d462735dc216c929b1b5a99dc984435

dp/wifi3.0/dp_main.c

@@ -1178,7 +1178,6 @@ budget_done:
 	return dp_budget - budget;
 }
 
-#ifdef DP_INTR_POLL_BASED
 /* dp_interrupt_timer()- timer poll for interrupts
  *
  * @arg: SoC Handle
@@ -1243,12 +1242,6 @@ static QDF_STATUS dp_soc_attach_poll(void *txrx_soc)
 
 	return QDF_STATUS_SUCCESS;
 }
-#else
-static QDF_STATUS dp_soc_attach_poll(void *txrx_soc)
-{
-	return -QDF_STATUS_E_NOSUPPORT;
-}
-#endif
 
 static QDF_STATUS dp_soc_interrupt_attach(void *txrx_soc);
 #if defined(CONFIG_MCL)