compat: Make compat helpers independent of CONFIG_COMPAT

Many of the compat time syscalls are also repurposed as 32 bit
native syscalls to provide backward compatibility while adding
new y2038 safe sycalls.
Enabling the helpers makes this possible.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>