i2c-tools: fix missing runtime library

When building with dynamic library support, i2c-tools utilities are
linked against the libi2c.so library. Current i2c-tools install commands
don't take this into account, which leads to the following run-time
error:

eeprog: error while loading shared libraries: libi2c.so.0: cannot open shared object file: No such file or directory

Use the native install target to fix that.

Cc: Angelo Compagnucci <angelo.compagnucci@gmail.com>
Cc: Matt Weber <matthew.weber@rockwellcollins.com>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>