lib/string_helpers: Introduce parse_int_array()

lib/string_helpers: Introduce parse_int_array()

Existing parse_inte_array_user() works with __user buffers only.
Separate array parsing from __user bits so the functionality can be
utilized with kernel buffers too.

Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Amadeusz Sławiński <amadeuszx.slawinski@linux.intel.com>
Signed-off-by: Cezary Rojewski <cezary.rojewski@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://patch.msgid.link/20250404090337.3564117-2-cezary.rojewski@intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>