[PATCH -next] drm/bridge: it6505: Fix build error without DRM_DP_HELPER

[Zheng Bin]

If DRM_DP_HELPER is not set, bulding fails:

ld: drivers/gpu/drm/bridge/ite-it6505.o: in function `it6505_link_training_work':
ite-it6505.c:(.text+0x50d8): undefined reference to `drm_dp_dpcd_write'
ld: ite-it6505.c:(.text+0x51c4): undefined reference to `drm_dp_link_train_clock_recovery_delay'
ld: ite-it6505.c:(.text+0x51d7): undefined reference to `drm_dp_dpcd_read_link_status'
ld: ite-it6505.c:(.text+0x51ec): undefined reference to `drm_dp_clock_recovery_ok'
ld: ite-it6505.c:(.text+0x5387): undefined reference to `drm_dp_get_adjust_request_voltage'
ld: ite-it6505.c:(.text+0x539d): undefined reference to `drm_dp_get_adjust_request_pre_emphasis'
ld: ite-it6505.c:(.text+0x5548): undefined reference to `drm_dp_link_train_channel_eq_delay'
ld: ite-it6505.c:(.text+0x555b): undefined reference to `drm_dp_dpcd_read_link_status'
ld: ite-it6505.c:(.text+0x5570): undefined reference to `drm_dp_clock_recovery_ok'
ld: ite-it6505.c:(.text+0x558d): undefined reference to `drm_dp_channel_eq_ok'
ld: ite-it6505.c:(.text+0x55da): undefined reference to `drm_dp_get_adjust_request_voltage'
ld: ite-it6505.c:(.text+0x55f2): undefined reference to `drm_dp_get_adjust_request_pre_emphasis'
ld: drivers/gpu/drm/bridge/ite-it6505.o: in function `it6505_bridge_detect':
ite-it6505.c:(.text+0x59f1): undefined reference to `drm_dp_dpcd_read'
ld: ite-it6505.c:(.text+0x5a16): undefined reference to `drm_dp_bw_code_to_link_rate'
ld: ite-it6505.c:(.text+0x5a87): undefined reference to `drm_dp_dpcd_read'
ld: ite-it6505.c:(.text+0x5ac1): undefined reference to `drm_dp_dpcd_write'
ld: ite-it6505.c:(.text+0x5d43): undefined reference to `drm_dp_link_rate_to_bw_code'

Fixes: b5c84a9edcd4 ("drm/bridge: add it6505 driver")
Reported-by: Hulk Robot <hulkci at huawei.com>
Signed-off-by: Zheng Bin <zhengbin13 at huawei.com>
---
 drivers/gpu/drm/bridge/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
index 007e5a282f67..2145b08f9534 100644
--- a/drivers/gpu/drm/bridge/Kconfig
+++ b/drivers/gpu/drm/bridge/Kconfig
@@ -78,6 +78,7 @@ config DRM_ITE_IT6505
         tristate "ITE IT6505 DisplayPort bridge"
         depends on OF
         select DRM_KMS_HELPER
+        select DRM_DP_HELPER
         select EXTCON
         help
           ITE IT6505 DisplayPort bridge chip driver.
--
2.31.1