Enable Rockchip I2C, SPI, PWM, thermal drivers.

Builtin are I2C (as it often required to control the pmic) and Thermal
drivers (to prevent thermal damage). SPI and PWM drivers configured as
modules
Signed-off-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>