regulator: palmas: Don't update tstep register for SMPS3 and SMPS7

SMPS3 and SMPS7 do not have tstep_addr setting, so current code actually
writes 0 to smps12_ctl (offset is 0) register when set_ramp_delay callback
is called for SMPS3 and SMPS7.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/drivers/regulator/palmas-regulator.c b/drivers/regulator/palmas-regulator.c
index 8e5331c..a741063 100644
--- a/drivers/regulator/palmas-regulator.c
+++ b/drivers/regulator/palmas-regulator.c
@@ -437,6 +437,13 @@
 	unsigned int addr = palmas_regs_info[id].tstep_addr;
 	int ret;
 
+	/* SMPS3 and SMPS7 do not have tstep_addr setting */
+	switch (id) {
+	case PALMAS_REG_SMPS3:
+	case PALMAS_REG_SMPS7:
+		return 0;
+	}
+
 	if (ramp_delay <= 0)
 		reg = 0;
 	else if (ramp_delay < 2500)