dm: Tidy up dump output when there are many devices

dm: Tidy up dump output when there are many devices

At present the 'Index' column of 'dm tree' assumes there is
two digits, this patch increase it to 3 digits.

It also aligns output of 'dm uclass', assuming the same 3 digits index.

The boards with CONFIG_PINCTRL_FULL activated have one pinconfig
by pin configuration, so they can have more than 100 devices
pinconfig (for example with stm32mp157c-ev1 board we have
106 pinconfig node).

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
Reviewed-by: Simon Glass <sjg@chromium.org>