chelsio: Remove remnants of CONFIG_CHELSIO_T1_COUGAR

CONFIG_CHELSIO_T1_COUGAR cannot be set (it appears nowhere in any
Kconfig files), and the code it protects could never build (cspi.h was
never added to the kernel tree).  Therefore it's pretty safe to remove
all vestiges of this dead code.

Signed-off-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: David S. Miller <davem@davemloft.net>