perf tools: Remove -Wcast-align

The present use of -Wcast-align causes the build to blow up on
SH due to generating a "cast increases required alignment of
target type" error on each invocation of list_for_each_entry().

It seems that this was previously reported and killed off in the
ia64 support patch, but nothing seems to have happened with
that. Presumably the same problem still remains there, too.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
LKML-Reference: <20091026054000.GA13517@linux-sh.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>