xtensa: nommu: fix USER_RING definition
xtensa: nommu: fix USER_RING definition

There's no kernel/user separation in noMMU and PS.RING may not exist.
Even if it exists it should not be used because TLB entries are not set
up for user ring on user pages.

Signed-off-by: Max Filippov <8c5ea195856807f4f02a6e0749c87ea6b7375f38@gmail.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs