poweroff: add poweroff for mt6323 pmic

this adds poweroff to bananapi r2 / mt7623 / mt6323 pmic

Signed-off-by: Frank Wunderlich <frank-w@public-files.de>
diff --git a/drivers/power/Makefile b/drivers/power/Makefile
index dd5bc0d..2dcc7bb 100644
--- a/drivers/power/Makefile
+++ b/drivers/power/Makefile
@@ -20,3 +20,4 @@
 obj-$(CONFIG_POWER_FSL) += power_fsl.o
 obj-$(CONFIG_POWER_I2C) += power_i2c.o
 obj-$(CONFIG_POWER_SPI) += power_spi.o
+obj-$(CONFIG_POWER_MT6323) += mt6323.o