perf/hw_breakpoint: Clean up headers

perf/hw_breakpoint: Clean up headers

Clean up headers:

 - Remove unused <linux/kallsyms.h>

 - Remove unused <linux/kprobes.h>

 - Remove unused <linux/module.h>

 - Remove unused <linux/smp.h>

 - Add <linux/export.h> for EXPORT_SYMBOL_GPL().

 - Add <linux/mutex.h> for mutex.

 - Sort alphabetically.

 - Move <linux/hw_breakpoint.h> to top to test it compiles on its own.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20220829124719.675715-4-elver@google.com