power: qpnp-qg: Update QG parameter reporting for debug_board

Report -EINVAL for cc_soc and charge_counter on a debug board
or missing battery.

While at it, clean up a few debug messages.

Change-Id: Ib4bb7b402db82570aad52dec4a327edcd79ac8d4
Signed-off-by: Kavya Nunna <knunna@codeaurora.org>