staging: kpc2000: kpc_i2c: Remove pldev from i2c_device structure

The i2c_device structure contains a member used to stash a pointer to
a platform_device. The driver contains no cases of this member being
used after initialization. Remove the unnecessary struct member and
the initialization of this member in the sole instance where the
driver creates a variable of type: struct i2c_device.

Signed-off-by: Geordan Neukum <gneukum1@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>