Added new fuctions to access vendor specified eeprom area

Signed-off-by: thomas.ruschival <thomas@ruschival.de>
Fixed Memory leak in tcv_init / add tcv_destroy

Memory leaks if read operation fails (quite common for i2c!)
No tcv_destroy function existed

Signed-off-by: Thomas Ruschival <thomas@ruschival.de>
Basic test was commented out
Merge branch 'tcv_destroy'