mfd: cros_ec: cleanup: remove unused fields from struct cros_ec_device

struct cros_ec_device has a superfluous "name" field. We can get all the
debugging info we need from the existing ec_name and phys_name fields, so
let's take out the extra field.

The printout also has sufficient info in it without explicitly adding
the transport.  Before this change:
  cros-ec-spi spi2.0: Chrome EC (SPI)

After this change:
  cros-ec-spi spi2.0: Chrome EC device registered

Signed-off-by: Bill Richardson <wfrichar@chromium.org>
Signed-off-by: Doug Anderson <dianders@chromium.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>