power: supply: ab8500_chargalg: improve kernel-doc

power: supply: ab8500_chargalg: improve kernel-doc

Correct "bad line" warnings and add descriptions for missing entries
to avoid these warnings:

ab8500_chargalg.c:173: warning: bad line:  is set
ab8500_chargalg.c:179: warning: bad line:  increased
ab8500_chargalg.c:247: warning: Function parameter or struct member
 't_hyst_norm' not described in 'ab8500_chargalg'
ab8500_chargalg.c:247: warning: Function parameter or struct member
 't_hyst_lowhigh' not described in 'ab8500_chargalg'
ab8500_chargalg.c:247: warning: Function parameter or struct member
 'ccm' not described in 'ab8500_chargalg'
ab8500_chargalg.c:247: warning: Function parameter or struct member
 'ac_chg' not described in 'ab8500_chargalg'
ab8500_chargalg.c:247: warning: Function parameter or struct member
 'usb_chg' not described in 'ab8500_chargalg'
ab8500_chargalg.c:308: warning: Function parameter or struct member
 'state' not described in 'ab8500_chargalg_state_to'
ab8500_chargalg.c:773: warning: Function parameter or struct member
 'di' not described in 'ab8500_chargalg_chg_curr_maxim'

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patch.msgid.link/20251111060009.1959425-1-rdunlap@infradead.org
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>