rng: rockchip_rng: Add compatible for RK3576

rng: rockchip_rng: Add compatible for RK3576

The RK3576 SoC contains a RKRNG block that can be used to generate
random numbers using the rockchip_rng driver.

Add compatible for RK3576 to support random numbers:

  => rng list
  RNG #0 - rng@2a410000

  => rng
  00000000: 36 dd ab 98 ec fb fe d1 cf 36 b3 e1 9b 3d 00 90  6........6...=..
  00000010: f5 84 de 75 6b 27 48 9e 13 62 12 6c 50 ca 47 1a  ...uk'H..b.lP.G.
  00000020: b3 4d fc 43 c5 b5 2d be 07 27 03 26 bb 69 61 2a  .M.C..-..'.&.ia*
  00000030: 6f 70 01 83 4e ce 91 7a 5a 6c 7c 00 43 87 3e c5  op..N..zZl|.C.>.

Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>