hx20: CHG_LIMIT_GET_LIMIT disables charge override

[DHowett]

Querying the charge limit with host command CHARGE_LIMIT_CONTROL mode CHG_LIMIT_GET_LIMIT reloads the charge limit from bbram, which overwrites the CHG_LIMIT_OVERRIDE flag.

Flag is set here (and not stored to bbram, because it is a one-time override):

EmbeddedController/board/hx20/battery.c

Lines 362 to 363 in 6e38e82

	if (p->modes & CHG_LIMIT_OVERRIDE)
	charging_maximum_level = charging_maximum_level | CHG_LIMIT_OVERRIDE;

and cleared when we read into charging_maximum_level here:

EmbeddedController/board/hx20/battery.c

Lines 365 to 366 in 6e38e82

	if (p->modes & CHG_LIMIT_GET_LIMIT) {
	system_get_bbram(SYSTEM_BBRAM_IDX_CHG_MAX, &charging_maximum_level);