bitmap-str.h is not self-contained, it uses bool type that is provided
in types.h and it uses __user annotation that is guaranteed to be included
with types.h. Add missing header(s) to follow IWYU (Include What You Use)
principle.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Yury Norov <yury.norov@gmail.com>

The bitmap-str.h uses mixed style for function prototypes. Drop
the 'extern' as it easier to read and makes style aligned with
a new code in the kernel.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Yury Norov <yury.norov@gmail.com>

lib/bitmap.c and corresponding include/linux/bitmap.h are intended to
hold functions related to operations on bitmaps, like bitmap_shift or
bitmap_set. Historically, some string-related operations like
bitmap_parse are also reside in lib/bitmap.c.

Now that the subsystem evolves, string-related bitmap operations became a
significant part of the file. Because they are quite different from the
other bitmap functions by nature, it's worth to split them to a separate
source/header files.

CC: Andrew Morton <akpm@linux-foundation.org>
CC: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
CC: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Yury Norov <yury.norov@gmail.com>