alpha: compile fixes

- jensen build: fix conflicting declarations for pci_alloc_consistent()
  and undefined virt_to_phys();

- SMP: arch/alpha/kernel/smp.c:124: warning: passing argument 2
       of '__cpu_test_and_set' discards qualifiers from pointer target type
  Interestingly, this only happens with gcc-4.2; gcc <= 4.1 and gcc-4.3
  are OK. Fixed with extra assignment.

Signed-off-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Richard Henderson <rth@twiddle.net>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>