iwlwifi: pcie: Configure shared interrupt vector in MSIX mode

In case the OS provides fewer interrupts than requested, different
causes will share the same interrupt vector as follow:
1.One interrupt less: non rx causes shared with FBQ.
2.Two interrupts less: non rx causes shared with FBQ and RSS.
3.More than two interrupts: we will use fewer RSS queues.

Also make the request depend on the number of online CPUs
instead of possible CPUs.

Signed-off-by: Haim Dreyfuss <haim.dreyfuss@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>

drivers/net/wireless/intel/iwlwifi/iwl-csr.h

@@ -589,6 +589,8 @@ enum dtd_diode_reg {
  * Causes for the FH register interrupts
  */
 enum msix_fh_int_causes {
+	MSIX_FH_INT_CAUSES_Q0			= BIT(0),
+	MSIX_FH_INT_CAUSES_Q1			= BIT(1),
 	MSIX_FH_INT_CAUSES_D2S_CH0_NUM		= BIT(16),
 	MSIX_FH_INT_CAUSES_D2S_CH1_NUM		= BIT(17),
 	MSIX_FH_INT_CAUSES_S2D			= BIT(19),