[PATCH] alpha: generic hweight build fix

From: Randy Dunlap <rdunlap@xenotime.net>

According to include/asm-alpha/bitops.h, only ALPHA_EV67 has hardware
hweight support, so ALPHA_EV6 needs to use GENERIC_HWEIGHT.

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Ernst Herzberg <earny@net4u.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>