i2c: merge all i2c_reg_read() and i2c_reg_write() into inline functions

All implementations of the functions i2c_reg_read() and
i2c_reg_write() are identical. We can save space and simplify the
code by converting these functions into inlines and putting them in
i2c.h.

Signed-off-by: Timur Tabi <timur@freescale.com>
Acked-By: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
14 files changed