doc: usb: chipidea: update the doc for OTG FSM

Since we have added otg version and HNP polling support, update
related documentation.

Signed-off-by: Peter Chen <peter.chen@nxp.com>

Documentation/usb/chipidea.txt

@@ -3,14 +3,17 @@
 To show how to demo OTG HNP and SRP functions via sys input files
 with 2 Freescale i.MX6Q sabre SD boards.
 
-1.1 How to enable OTG FSM in menuconfig
+1.1 How to enable OTG FSM
 ---------------------------------------
-Select CONFIG_USB_OTG_FSM, rebuild kernel Image and modules.
-If you want to check some internal variables for otg fsm,
-mount debugfs, there are 2 files which can show otg fsm
-variables and some controller registers value:
+1.1.1 Select CONFIG_USB_OTG_FSM in menuconfig, rebuild kernel
+Image and modules. If you want to check some internal
+variables for otg fsm, mount debugfs, there are 2 files
+which can show otg fsm variables and some controller registers value:
 cat /sys/kernel/debug/ci_hdrc.0/otg
 cat /sys/kernel/debug/ci_hdrc.0/registers
+1.1.2 Add below entries in your dts file for your controller node
+	otg-rev = <0x0200>;
+	adp-disable;
 
 1.2 Test operations
 -------------------