bnx2x: prevent masked MCP parities from appearing

During flows which mask block attentions (e.g., register dump) all parities
are masked. However, unlike other blocks the MCP's attention is not masked
inside the block but rather the indication to the driver. If another attention
(e.g., link change) will occour while there's an MCP parity, the driver will
ignore the fact that the parity is masked and erroneously report a parity.

This patch forces the driver to read the MCP masking while checking for
parities.

Signed-off-by: Yuval Mintz <yuvalmin@broadcom.com>
Signed-off-by: Ariel Elior <ariele@broadcom.com>
Signed-off-by: Eilon Greenstein <eilong@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>