ARM: sti: Add STiH407 Kconfig entry to select STIH407_RESET

The STiH407 is a STMicroelectronics Digital Consumer electronics
family, targetted at set-top-box and other audio/video applications.

This patch selects the reset controller driver for this family which
is essential to take various IP's on the SoC out of powerdown / reset.

Signed-off-by: Peter Griffin <peter.griffin@linaro.org>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Maxime Coquelin <maxime.coquelin@st.com>