A debtor's attorney, or any professional person employed by the debtor (in the debtor's sole discretion), the Oversight Board (in the Oversight Board's sole discretion), a committee under section 1103 of title 11, or a trustee appointed by the court under section 926 of title 11, may apply to the court not more than once every 120 days after an order for relief in a case under this subchapter, or more often if the court permits, for such compensation for services rendered before the date of such an application or reimbursement for expenses incurred before such date as is provided under section 2176 of this title.