rockchip: include cru_rk3588.h and define rockchip_cru for RK3588

rockchip: include cru_rk3588.h and define rockchip_cru for RK3588

fix following error found by clang:

  CC      arch/arm/mach-rockchip/cpu-info.o
arch/arm/mach-rockchip/cpu-info.c:23:13: error: incomplete definition of type 'struct rockchip_cru'
   23 |         switch (cru->glb_rst_st) {
      |                 ~~~^
./arch/arm/include/asm/arch-rockchip/clock.h:181:8: note: forward declaration of 'struct rockchip_cru'
  181 | struct rockchip_cru;
      |        ^
1 error generated.

Signed-off-by: FUKAUMI Naoki <naoki@radxa.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>