bnx2x: Enhanced self test

Added registers, memories, loopback, nvram, interrupt and link tests to
the self-test

Signed-off-by: Yitchak Gertner <gertner@broadcom.com>
Signed-off-by: Eilon Greenstein <eilong@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>