cleanup arch/alpha/Makefile

- binutils 2.7 is far below the current minimum supported version,
  and there's therefore no longer a need for an extra test

- since even gcc 3.2 already supports all options used we can use them
  unconditionally

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>