soc/mediatek/mt8192: Correct return value of VM18 voltage

The voltage of vm18 should be microvolt instead of millivolt.

BUG=b:155253454
BRANCH=none
TEST=boot asurada correctly

Signed-off-by: Hsin-Hsiung Wang <hsin-hsiung.wang@mediatek.com>
Change-Id: Iea5b46c1df358dc350506d29cc033d01631b37b0
Reviewed-on: https://review.coreboot.org/c/coreboot/+/48110
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Yu-Ping Wu <yupingso@google.com>
diff --git a/src/soc/mediatek/mt8192/mt6359p.c b/src/soc/mediatek/mt8192/mt6359p.c
index 1646e53..a8e93ca 100644
--- a/src/soc/mediatek/mt8192/mt6359p.c
+++ b/src/soc/mediatek/mt8192/mt6359p.c
@@ -417,7 +417,7 @@
 
 	reg_vol = 100 * mt6359p_read_field(PMIC_VM18_ANA_CON0, 0xF, VM18_VOL_REG_SHIFT);
 	reg_cali = 10 * mt6359p_read_field(PMIC_VM18_ANA_CON0, 0xF, 0);
-	return 600 + reg_vol + reg_cali;
+	return 1000 * (VM18_VOL_OFFSET + reg_vol + reg_cali);
 }
 
 static void init_pmif_arb(void)