Add read/write functions to transceiver

Allow direct access to non-msa specified data or other subdevices
- Write access only to registers >96
- Read access not yet sanity checked.

Signed-off-by: Thomas Ruschival <thomas@ruschival.de>
Merge branch 'RawReadWrite' of https://github.com/truschival/libtcv into truschival-RawReadWrite

Conflicts:
	include/libtcv/tcv.h
Merge branch 'truschival-RawReadWrite'