mm/Kconfig: Remove dependency on QCOM_MEM_OFFLINE for movable zone

Enabling the movable zone shouldn't depend on QCOM_MEM_OFFLINE,
so remove the dependency.

Change-Id: Id5bd1a7b79adbf6f85c2007cd7d690a387258c83
Signed-off-by: Isaac J. Manjarres <isaacm@codeaurora.org>