be2net: set EQ DB clear-intr bit in be_open()

[ Upstream commit 4cad9f3b61c7268fa89ab8096e23202300399b5d ]

On BE3, if the clear-interrupt bit of the EQ doorbell is not set the first
time it is armed, ocassionally we have observed that the EQ doesn't raise
anymore interrupts even if it is in armed state.
This patch fixes this by setting the clear-interrupt bit when EQs are
armed for the first time in be_open().

Signed-off-by: Suresh Reddy <Suresh.Reddy@emulex.com>
Signed-off-by: Sathya Perla <sathya.perla@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>