Revert "Loongarch: Support loongarch avec"

This reverts commit 760d7e71.

This results in build failures and has other issues according to Tianyang.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Tianyang Zhang <zhangtianyang@loongson.cn>
Closes: https://lore.kernel.org/oe-kbuild-all/202406240451.ygBFNyJ3-lkp@intel.com/