regulator: ab8500-ext: Add support for AB8505/AB9540

The external regulator driver checks for old AB8500 HW
to apply a fix. This patch adds a check to see that
it is a AB8500 (not AB8505/AB9540).

Signed-off-by: Bengt Jonsson <bengt.g.jonsson@stericsson.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/drivers/regulator/ab8500-ext.c b/drivers/regulator/ab8500-ext.c
index 21b9bfb..debae34b 100644
--- a/drivers/regulator/ab8500-ext.c
+++ b/drivers/regulator/ab8500-ext.c
@@ -369,7 +369,7 @@
 	}
 
 	/* check for AB8500 2.x */
-	if (abx500_get_chip_id(&pdev->dev) < 0x30) {
+	if (is_ab8500_2p0_or_earlier(ab8500)) {
 		struct ab8500_ext_regulator_info *info;
 
 		/* VextSupply3LPn is inverted on AB8500 2.x */