MAINTAINERS: Add ST's CPUFreq driver to the STI file list

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

MAINTAINERS

@@ -1638,6 +1638,7 @@ F:	arch/arm/boot/dts/sti*
 F:	drivers/char/hw_random/st-rng.c
 F:	drivers/clocksource/arm_global_timer.c
 F:	drivers/clocksource/clksrc_st_lpc.c
+F:	drivers/cpufreq/sti-cpufreq.c
 F:	drivers/i2c/busses/i2c-st.c
 F:	drivers/media/rc/st_rc.c
 F:	drivers/media/platform/sti/c8sectpfe/