bnxt_en: Fix ethtool -d byte order for 32-bit values

For version 1 register dump that includes the PCIe stats, the existing
code incorrectly assumes that all PCIe stats are 64-bit values.  Fix it
by using an array containing the starting and ending index of the 32-bit
values.  The loop in bnxt_get_regs() will use the array to do proper
endian swap for the 32-bit values.

Fixes: b5d600b0 ("bnxt_en: Add support for 'ethtool -d'")
Reviewed-by: Shruti Parab <shruti.parab@broadcom.com>
Reviewed-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Reviewed-by: Andy Gospodarek <andrew.gospodarek@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>