octeon_ep: explicitly test for firmware ready value

The firmware ready value is 1, and get firmware ready status
function should explicitly test for that value. The firmware
ready value read will be 2 after driver load, and on unbind
till firmware rewrites the firmware ready back to 0, the value
seen by driver will be 2, which should be regarded as not ready.

Fixes: 10c073e4

 ("octeon_ep: defer probe if firmware not ready")
Signed-off-by: Shinas Rasheed <srasheed@marvell.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>