drm/sun4i: hdmi: Use more portable I/O helpers

readsb/writesb are unavailable on some architectures. In preparation for
removing the Kconfig architecture dependency, switch to the equivalent
but more portable ioread/write8_rep helpers.

Reported-by: kernel test robot <[e-mail]>
Signed-off-by: Samuel Holland <[e-mail]>
Reviewed-by: Jernej Skrabec <[e-mail]>
Signed-off-by: Maxime Ripard <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/sun4i/sun4i_hdmi_i2c.c

···
 		return -EIO;
 
 	if (read)
-		readsb(hdmi->base + hdmi->variant->ddc_fifo_reg, buf, len);
+		ioread8_rep(hdmi->base + hdmi->variant->ddc_fifo_reg, buf, len);
 	else
-		writesb(hdmi->base + hdmi->variant->ddc_fifo_reg, buf, len);
+		iowrite8_rep(hdmi->base + hdmi->variant->ddc_fifo_reg, buf, len);
 
 	/* Clear FIFO request bit by forcing a write to that bit */
 	regmap_field_force_write(hdmi->field_ddc_int_status,