arm: stm32mp: move the get_otp helper function in bsec

As the get_otp() helper function in bsec are common for all STM32MP family,
move this function in bsec driver

Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
diff --git a/arch/arm/mach-stm32mp/bsec.c b/arch/arm/mach-stm32mp/bsec.c
index 506caa0..c00130b 100644
--- a/arch/arm/mach-stm32mp/bsec.c
+++ b/arch/arm/mach-stm32mp/bsec.c
@@ -632,3 +632,20 @@
 
 	return false;
 }
+
+u32 get_otp(int index, int shift, int mask)
+{
+	int ret;
+	struct udevice *dev;
+	u32 otp = 0;
+
+	ret = uclass_get_device_by_driver(UCLASS_MISC,
+					  DM_DRIVER_GET(stm32mp_bsec),
+					  &dev);
+
+	if (!ret)
+		ret = misc_read(dev, STM32_BSEC_SHADOW(index),
+				&otp, sizeof(otp));
+
+	return (otp >> shift) & mask;
+}