drm/hisilicon/kirin: Include linux/io.h for readl()/writel()

Include linux/io.h for readl()/writel().

When built on x86_64 w/ COMPILE_TEST=y:
../drivers/gpu/drm/hisilicon/kirin/dw_dsi_reg.h:93:16: error: implicit declaration of function ‘readl’ [-Werror=implicit-function-declaration]
   93 |         orig = readl(addr);
      |                ^~~~~
../drivers/gpu/drm/hisilicon/kirin/dw_dsi_reg.h:96:9: error: implicit declaration of function ‘writel’ [-Werror=implicit-function-declaration]
   96 |         writel(tmp, addr);
      |         ^~~~~~

Cc: Xinliang Liu <[email protected]>
Cc: Tian Tao <[email protected]>
Cc: Xinwei Kong <[email protected]>
Cc: Sumit Semwal <[email protected]>
Cc: Yongqin Liu <[email protected]>
Cc: John Stultz <[email protected]>
Signed-off-by: Ville Syrjälä <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
Acked-by: John Stultz <[email protected]>

0 files changed, 0 insertions, 0 deletions