iwlwifi: pcie: set RB chunk size back to 64

128 byte chunk size is supported only on PCIe and not
on IOSF. For now, change it back to 64 byte.

Reported-by: Oren Givon <oren.givon@intel.com>
Signed-off-by: Sara Sharon <sara.sharon@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/rx.c b/drivers/net/wireless/intel/iwlwifi/pcie/rx.c
index a310fd2..509f790 100644
--- a/drivers/net/wireless/intel/iwlwifi/pcie/rx.c
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/rx.c
@@ -801,11 +801,10 @@
 
 	/*
 	 * Activate DMA snooping.
-	 * Set RX DMA chunk size to 128 bit
+	 * Set RX DMA chunk size to 64B
 	 * Default queue is 0
 	 */
 	iwl_write_prph(trans, RFH_GEN_CFG, RFH_GEN_CFG_RFH_DMA_SNOOP |
-		       RFH_GEN_CFG_RB_CHUNK_SIZE |
 		       (DEFAULT_RXQ_NUM << RFH_GEN_CFG_DEFAULT_RXQ_NUM_POS) |
 		       RFH_GEN_CFG_SERVICE_DMA_SNOOP);
 	/* Enable the relevant rx queues */