i2c: busses: i2c-eg20t: Fix 'bad line' issue and provide description for 'msgs' param

Fixes the following W=1 kernel build warning(s):

 drivers/i2c/busses/i2c-eg20t.c:151: warning: bad line:                          PCH i2c controller
 drivers/i2c/busses/i2c-eg20t.c:369: warning: Function parameter or member 'msgs' not described in 'pch_i2c_writebytes'

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>