arm/ls102xa:add hwconfig setting to support disable unused devices

DEVDISRn registers provides a mechanism for gating clocks of IP blocks
that are not used. Here we implement hwconfig option to allow users
to disable unused peripherals on the board.

For ex. If eSDHC/qDMA/eDMA are unused and with disabled status in dts,
User can enable CONFIG_FSL_DEVICE_DISABLE and set "devdis:esdhc,qdma,edma"
in hwconfig, thus ESDHC controller & eDMA/qDMA will be clock gated to
save more power.

Signed-off-by: Zhuoyu Zhang <Zhuoyu.Zhang@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index 5218b91..8d0fc3c 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -35,3 +35,4 @@
 obj-$(CONFIG_FSL_SEC_MON) += fsl_sec_mon.o
 obj-$(CONFIG_PCA9551_LED) += pca9551_led.o
 obj-$(CONFIG_RESET) += reset-uclass.o
+obj-$(CONFIG_FSL_DEVICE_DISABLE) += fsl_devdis.o