mfd: cpcap: Add missing include dependencies

This fixes compilation for files, that try to include the
cpcap header in alphabetically sorted #include lists.

Acked-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>