sfc: Fix module EEPROM reporting for QSFP modules

[ Upstream commit 281900a9 ]

The sfc driver does not report QSFP module EEPROM contents correctly
as only the first page is fetched from hardware.

Commit 0e1a2a3e ("ethtool: Add SFF-8436 and SFF-8636 max EEPROM
length definitions") added ETH_MODULE_SFF_8436_MAX_LEN for the overall
size of the EEPROM info, so use that to report the full EEPROM contents.

Fixes: 9b17010d ("sfc: Add ethtool -m support for QSFP modules")
Signed-off-by: Andy Moreton <andy.moreton@amd.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>