drm/bridge/sii8620: fix dependency on extcon

stable inclusion
from stable-5.10.50
commit 45415d1f99291d81ee945912d4e1d61c43cf0283
bugzilla: 174522 https://gitee.com/openeuler/kernel/issues/I4DNFY

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=45415d1f99291d81ee945912d4e1d61c43cf0283

--------------------------------

[ Upstream commit 08319adb ]

The DRM_SIL_SII8620 kconfig has a weak `imply` dependency
on EXTCON, which causes issues when sii8620 is built
as a builtin and EXTCON is built as a module.

The symptoms are 'undefined reference' errors caused
by the symbols in EXTCON not being available
to the sii8620 driver.

Fixes: 68883844 ("drm/bridge/sii8620: use micro-USB cable detection logic to detect MHL")
Reported-by: Nkernel test robot <lkp@intel.com>
Signed-off-by: NRobert Foss <robert.foss@linaro.org>
Reviewed-by: NRandy Dunlap <rdunlap@infradead.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210419090124.153560-1-robert.foss@linaro.orgSigned-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: NWeilong Chen <chenweilong@huawei.com>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

drivers/gpu/drm/bridge/Kconfig

@@ -130,7 +130,7 @@ config DRM_SIL_SII8620
 	tristate "Silicon Image SII8620 HDMI/MHL bridge"
 	depends on OF
 	select DRM_KMS_HELPER
-	imply EXTCON
+	select EXTCON
 	depends on RC_CORE || !RC_CORE
 	help
 	  Silicon Image SII8620 HDMI/MHL bridge chip driver.