treewide: fix typo "previlege"

There are some spelling mistakes of 'previlege' in comments which
should be 'privilege'.

Fix them and add it to scripts/spelling.txt.

The typo in arch/loongarch/kvm/main.c was corrected by a different
patch [1] and is therefore not included in this submission.

[1]. https://lore.kernel.org/all/20250420142208.2252280-1-wheatfox17@icloud.com/

Link: https://lkml.kernel.org/r/46AD404E411A4BAC+20250421074910.66988-1-wangyuli@uniontech.com


Signed-off-by: WangYuli <wangyuli@uniontech.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>