update the documentation wrt kernel and device memory and frame sizes

[rottaran]

Find the places in the latex documents that mention frames, device and kernel memory. The new rules are as follows: The start address is restricted to 4KiB alignment, the size of frames is restricted to power-of-two multiples of 4KiB. You can allocate "Frames" from Kernel Memory objects, which is implemented by the MemoryRegion kernel objects and these can have arbitrary size in multiples of 4KiB.