Added second set of recovery options for DB845c

Based on issued 96boards#833, there may be a problem with
our instructions. Until an absolute solution is
found, we will add both methods in the docs.
If the first (original method) does not work,
users will be able to try out the second
method.

Signed-off-by: Robert Wolff <robert.wolff@linaro.org>

consumer/dragonboard/dragonboard845c/installation/board-recovery.md

@@ -32,6 +32,16 @@ In order to force the DB845c to boot on USB (EDL mode), you need to press the on
 * Power on the device using the proper power supply
 * Connect the USB3 Type C (5) between the Linux PC and the board
 
+If the above instructions do not work, please try the following:
+
+- Set the switch "DIP_SW" to "0 1 1 0 0 0"
+- (Turn on SW2 on the dip switch to enable the USB2.0 debug port
+- Turn on SW3 on the Dip Switch to enable the auto power up on USB-C cable connection)
+- Power off the board and make sure the USB type-C cable is not plugged into the board
+- Press button 18 (e.g. marked with F_DL), and
+- Connect the USB3 Type C (5) between the Linux PC and the board
+
+*Warning*: putting the device into EDL mode while the device is powered or when USB is plugged can cause damage to the board.
 
 ### Flashing the device