few changes to drivers, no kernel config was added. As the SoCs are quite
old and the code is unmaintained start the process of removing support by
deleting the header file and code that depends on it along with the macro
SOC_OMAP3. Other Ti SoCs shouldn't be affected, other than for us to have
less code to maintain.
Differential Revision: https://reviews.freebsd.org/D936
Reviewed by: rpaulo, loos