modpost: i2c aliases need no trailing wildcard

Not all device types need a wildcard at the end of their module
aliases. In particular, for i2c module aliases, the trailing wildcard
is not only unneeded, it could also cause the wrong driver to be
loaded.

As I2C devices have no IDs, i2c module aliases are simple, arbitrary
device names. For example:

$ /sbin/modinfo lm90
filename:       /lib/modules/2.6.25-git18/kernel/drivers/hwmon/lm90.ko
author:         Jean Delvare <khali@linux-fr.org>
description:    LM90/ADM1032 driver
license:        GPL
vermagic:       2.6.25-git18 mod_unload
depends:        hwmon
alias:          i2c:lm90*
alias:          i2c:adm1032*
alias:          i2c:lm99*
alias:          i2c:lm86*
alias:          i2c:max6657*
alias:          i2c:adt7461*
alias:          i2c:max6680*
$

This would cause trouble if one I2C chip name matches the beginning of
another I2C chip name and both chips are supported by different
drivers. For example, an i2c device named lm9042 would cause the lm90
driver...