[ALPS08824370] aov apu: add more debug msg for SCP IPI

[Description]
1. add more debug msg for SCP IPI
2. fix typo in a returned value checking

[Test]
build pass, aov apu unit test pass

MTK-Commit-Id: 3f92226961d9d33a4f76f7fa28a11dfcd52eff81

CR-Id: ALPS08824370
Feature: np_micro
Change-Id: I2844addab9b053c09ca065b92380b35c7928c745
Signed-off-by: Nixy Hsu <nixy.hsu@mediatek.com>