Input: spear-keyboard - add 6x6 keypad matrix definitions

Add 6x6 keypad matrix and rename 9x9 keymap

Signed-off-by: Rajeev Kumar <rajeev-dlh.kumar@st.com>
Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>