ANDROID: GKI: rockchip: Add symbols for pwm driver

1 function symbol(s) added
  'struct pwm_device * devm_of_pwm_get(struct device *, struct device_node *, const char *)'

Bug: 239396464
Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
Signed-off-by: Bian Jin chen <kenjc.bian@rock-chips.com>
Change-Id: Idc854ea25c83982853eeb3d3d09c84c440d0af52