mailbox: qcom-apcs-ipc: re-organize compatibles with fallbacks

Similarly to previous commit e1722588 ("mailbox: qcom-apcs-ipc: do
not grow the of_device_id"), move compatibles with fallbacks in the
of_device_id table, to indicate these are not necessary.  This only
shuffles the code.  No functional impact.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>