powerpc/configs/6s: Drop obsolete crypto ALGs

These algorithms were marked obsolete in commit 1674aea5 ("crypto:
Kconfig - mark unused ciphers as obsolete").

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230414132415.821564-4-mpe@ellerman.id.au