uninline atl1e_setup_mac_ctrl()

There doesn't seem to be a compelling reason why atl1e_setup_mac_ctrl()
is marked as "inline":

It's not used in any place where speed would matter much, and as long as
it has only one caller non-ancient gcc versions anyway inline it
automatically.

This patch fixes the following compile error with gcc 3.4:

    CC      drivers/net/atl1e/atl1e_main.o
  atl1e_main.c: In function `atl1e_check_link':
  atl1e_main.c:50: sorry, unimplemented: inlining failed in call to
  atl1e_main.c:196: sorry, unimplemented: called from here

Reported-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>