mhi: core: Enable parsing of dev window from dt

Enable parsing of device window size from device tree
and calculating the appropriate addressing limitations.

Change-Id: I252a593a74f0cc00e6295a45d4d13db6c79cdfca
Signed-off-by: Andrei Danaila <adanaila@codeaurora.org>
Signed-off-by: Tony Truong <truong@codeaurora.org>