pwm: mtk: add support for MediaTek MT7988 SoC

This patch adds PWM support for MediaTek MT7988 SoC.

diff --git a/drivers/pwm/pwm-mtk.c b/drivers/pwm/pwm-mtk.c
index 605142e..11e7444 100644
--- a/drivers/pwm/pwm-mtk.c
+++ b/drivers/pwm/pwm-mtk.c
@@ -205,12 +205,19 @@
 	.reg_ver = PWM_REG_V1,
 };
 
+static const struct mtk_pwm_soc mt7988_data = {
+	.num_pwms = 8,
+	.pwm45_fixup = false,
+	.reg_ver = PWM_REG_V2,
+};
+
 static const struct udevice_id mtk_pwm_ids[] = {
 	{ .compatible = "mediatek,mt7622-pwm", .data = (ulong)&mt7622_data },
 	{ .compatible = "mediatek,mt7623-pwm", .data = (ulong)&mt7623_data },
 	{ .compatible = "mediatek,mt7629-pwm", .data = (ulong)&mt7629_data },
 	{ .compatible = "mediatek,mt7981-pwm", .data = (ulong)&mt7981_data },
 	{ .compatible = "mediatek,mt7986-pwm", .data = (ulong)&mt7986_data },
+	{ .compatible = "mediatek,mt7988-pwm", .data = (ulong)&mt7988_data },
 	{ }
 };