iwl3945: remove unnecessary call to apm_ops.reset()

Now that we're unconditionally using apm_ops.stop() to reset and power-down
the device in __iwl3945_down(), the apm_ops.reset() is redundant.  Removing
this call will also allow us to remove iwl3945_apm_reset().

Remove unneeded iwl_clear_bit(CSR_GP_CNTRL_REG_FLAG_MAC_ACCESS_REQ) because
this bit will be set again very soon in iwl3945_hw_txq_ctx_stop() and other
following calls.

Signed-off-by: Ben Cahill <ben.m.cahill@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>