tg3: Create aliases for rx producer mailbox regs

The rx producer mailbox registers are used in several spots in the code.
The addition of TG3_64BIT_REG_LOW makes register references
uncomfortably long.  This patch creates an alias for the standard and
jumbo ring producer index registers to make the code cleaner.

Signed-off-by: Matt Carlson <mcarlson@broadcom.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/tg3.h b/drivers/net/tg3.h
index 715df2b..bbfbc5e 100644
--- a/drivers/net/tg3.h
+++ b/drivers/net/tg3.h
@@ -242,7 +242,11 @@
 #define MAILBOX_GENERAL_7		0x00000258 /* 64-bit */
 #define MAILBOX_RELOAD_STAT		0x00000260 /* 64-bit */
 #define MAILBOX_RCV_STD_PROD_IDX	0x00000268 /* 64-bit */
+#define TG3_RX_STD_PROD_IDX_REG		(MAILBOX_RCV_STD_PROD_IDX + \
+					 TG3_64BIT_REG_LOW)
 #define MAILBOX_RCV_JUMBO_PROD_IDX	0x00000270 /* 64-bit */
+#define TG3_RX_JMB_PROD_IDX_REG		(MAILBOX_RCV_JUMBO_PROD_IDX + \
+					 TG3_64BIT_REG_LOW)
 #define MAILBOX_RCV_MINI_PROD_IDX	0x00000278 /* 64-bit */
 #define MAILBOX_RCVRET_CON_IDX_0	0x00000280 /* 64-bit */
 #define MAILBOX_RCVRET_CON_IDX_1	0x00000288 /* 64-bit */