move ETMEM feature CONFIG to mm/Kconfig and add architecture dependency

euleros inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I7RO5Q
Reference: https://gitee.com/openeuler/kernel/commit/d7b8dcbecdc40d98d20812176f57d7f72fa3f6b9



-------------------------------------------------

The original etmem feature failed to compile a specific architecture,
for example, powerpc, because the architecture is not specified.

This patch is move ETMEM feature CONFIG to mm/Kconfig and add
architecture.

Signed-off-by: liubo <liubo254@huawei.com>
Reviewed-by: jingxiangfeng 00447129 <jingxiangfeng@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>