ANDROID: GKI: rockchip: Enable symbols for pwm_bl

Functions changes summary: 0 Removed, 0 Changed, 1 Added function
Variables changes summary: 0 Removed, 0 Changed, 0 Added variable

1 Added function:

  [A] 'function int pwm_adjust_config(pwm_device*)'

Bug: 194515348
Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: Ic944cb67431d2da199a12f926f6e9248235a3abf