USB: CP210X Replace CP2101 with CP210x

This patch replaces the string "CP2101" with "CP210x" within cp210x.c
This is to reduce confusion about the fact that the driver is actually
compatible with CP2101, CP2102 and CP2103 devices.

Signed-off-by: Craig Shelley <craig@microtron.org.uk>
(Fixed some collisions merging)

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>