bnxt_en: Use register window 6 instead of 5 to read the PHC

Some older Broadcom debug tools use window 5 and may conflict, so switch
to use window 6 instead.

Fixes: 118612d5 ("bnxt_en: Add PTP clock APIs, ioctls, and ethtool methods")
Reviewed-by: Andy Gospodarek <gospo@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.h

@@ -10,8 +10,8 @@
 #ifndef BNXT_PTP_H
 #define BNXT_PTP_H
 
-#define BNXT_PTP_GRC_WIN	5
-#define BNXT_PTP_GRC_WIN_BASE	0x5000
+#define BNXT_PTP_GRC_WIN	6
+#define BNXT_PTP_GRC_WIN_BASE	0x6000
 
 #define BNXT_MAX_PHC_DRIFT	31000000
 #define BNXT_LO_TIMER_MASK	0x0000ffffffffUL