soc: qcom: mem-offline: BUG_ON when hw online request fails

Provide a config option to BUG_ON when the hardware memory online
fails. This helps to catch such issues much quicker and avoids the
later side effects of such online failures.

Change-Id: Ifa39962593e0d2e75bdb164d91755aff47d39058
Signed-off-by: Sudarshan Rajagopalan <sudaraja@codeaurora.org>