soc: qcom: mem-offline: turn off ddr refresh under MEM_CANCEL_ONLINE

mem-offline driver turns on ddr refresh logic during the
MEM_GOING_ONLINE event. But when fail to online pages, which the same
is notified as MEM_CANCEL_ONLINE event, turn off the ddr refresh logic.

Change-Id: I550405a60eb17059e4fd7d89eeccab60fceccc64
Signed-off-by: Charan Teja Reddy <charante@codeaurora.org>
Signed-off-by: Sudarshan Rajagopalan <sudaraja@codeaurora.org>