feat(security): add Security Overview page

[shiva-ti]

• create new Security_overview.rst as the landing page for security documentation
• provide comprehensive security framework details and features overview
• add references to Security_overview in platform TOC files (AM62X, AM62AX, AM62PX, AM62LX)
• add cross-reference links in related security documentation

[shiva-ti]

@ti-kamlesh @Pratham-T @jsuhaas22 @vishalmti @kavitha-malarvizhi FYR, Please review

[cshilwant]

also checkout the errors reported by vale at https://github.com/TexasInstruments/processor-sdk-doc/pull/533/files

[manorit2001]

Hey @shiva-ti , most of it seems generic to me that would be applicable to most of the platforms, some things might not be tested for other platforms like we don't think J7 platforms have tested SELinux but I think rest of the things we can keep in common I feel, if possible, I would prefer it being incorporated too

[shiva-ti]

Hey @shiva-ti , most of it seems generic to me that would be applicable to most of the platforms, some things might not be tested for other platforms like we don't think J7 platforms have tested SELinux but I think rest of the things we can keep in common I feel, if possible, I would prefer it being incorporated too

@manorit2001 added the support for J7 platforms as well, please check. For reference:

[manorit2001]

Thanks for the update!