Documentation: Minor changes to men-chameleon-bus.txt

Change men-chameleon-bus.txt according to the comments made by Randy Dunlap in
https://lkml.org/lkml/2015/7/17/691

.

These are:
* Some minor gramatical changes
* Spelling fixes
* Write the word "Chameleon" capitalized throughout the whole document
* Explain MEN as MEN Mikro Elektronik GmbH.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>