kern-tools: fix python 3.12 warning

kern-tools: fix python 3.12 warning

Integrating the following commit:

  Author: hongxu <hongxu.jia@eng.windriver.com>
  Date:   Tue Dec 17 01:47:19 2024 -0800

      symbol_why: fix SyntaxWarning for RegEx calls on Python 3.12

      Python 3.12 emmits a SyntaxWarning when using unescaped
      character inside a RegEx string.
      '''
      recipe-sysroot-native/usr/bin/symbol_why.py:161: SyntaxWarning: invalid escape sequence '\.'
        if re.match( ".*\.config", opt ):
      recipe-sysroot-native/usr/bin/symbol_why.py:216: SyntaxWarning: invalid escape sequence '\w'
        x = re.match( "^# .*Linux/\w*\s*([0-9]*\.[0-9]*\.[0-9]*).*Kernel Configuration", line )
      recipe-sysroot-native/usr/bin/symbol_why.py:495: SyntaxWarning: invalid escape sequence '\s'
        if re.search( "^#\s*CONFIG_", option ):
      '''

      According to [1], use raw strings for regular expression

      [1] https://docs.python.org/dev/whatsnew/3.12.html#other-language-changes

      Signed-off-by: Hongxu Jia <hongxu.jia@windriver.com>
Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>