atl1c: Fix hardware type check for enabling OTP CLK

Commit 496c185c "atl1c: Add support
for Atheros AR8152 and AR8152" added the condition:

             if (hw->nic_type == athr_l1c || hw->nic_type == athr_l2c_b)

for enabling OTP CLK, and the condition:

             if (hw->nic_type == athr_l1c || hw->nic_type == athr_l2c)

for disabling OTP CLK.  Since the two previously defined hardware
types are athr_l1c and athr_l2c, the latter condition appears to be
the correct one.  Change the former to match.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>