Using mbed.h instead of direct include of blockdevice

[bridadan]

BlockDevice was brought into the mbed namespace with ARMmbed/mbed-os#7663.

This breaks the current "direct include" of BlockDevice.h that is currently in use. This PR moves to including mbed.h so the namespace is used correctly. This should be backwards compatible with previous releases of Mbed OS as well.

[bridadan]

@dlfryar reports this is a good fix!

[dlfryar-zz]

+1 looks good solved issues encountered when PR #7663 moved the namespace

[0xc0170]

This repo does not use any of the mbed namespace therfore 7663 caused a breakage (good use case for this change - it's breaking for someone!).

Looking at the fix here, not certain that include "mbed.h" everywhere is a fix. Is this repository used as one of the modules? Adding mbed.h might cause conflicts for other modules and increase compilation time. I would propose something similar to http://www.gotw.ca/publications/migrating_to_namespaces.htm.

For the cpp files here, using mbed::BlockDevice after includes. and in the header files, do mbed::Blockdevice (not using there), similar to what PR #39 did.

This change comes with 5.10

[bridadan]

Thanks for the tip @0xc0170! I'll update the PR to use the namespace.

[bridadan]

Actually, looks like #39 already did it the better way, may be we can just take that one? Closing this for now.