Revert "spi: Fix OCTAL mode support"

This reverts commit 4bcb8e4c which is
commit d6a711a8 upstream.

It breaks the Android kernel abi and can be brought back in the future
in an abi-safe way if it is really needed.

Bug: 161946584
Change-Id: I005a5c904b9fca455650e0594726719f6123487d
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>