Input: spear_keyboard - fix clock handling during suspend/resume

SPEAr keyboard should normally disable clock during suspend and enable it
during resume.

For cases where it is expected to act as a wakeup source the clock can
remain in the same state i.e. kept enabled if it is being used.

Signed-off-by: Shiraz Hashim <shiraz.hashim@st.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>