DRA72x-evm uses TPS65917 PMIC. Add the node.

NOTE: LDO2 is actually unused, but the usage if any is expected to be
between 1.8 to 3.3v IO voltage. So define the node.

NOTE: Interrupt used is crossbar number based.
Tested-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Keerthy <j-keerthy@ti.com>
Tested-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>