drm/amd/display: Fix 32-bit divide error in wait_for_alt_mode

When building arm32 allyesconfig:

ld.lld: error: undefined symbol: __aeabi_uldivmod
>>> referenced by dc_link.c
>>> gpu/drm/amd/display/dc/core/dc_link.o:(wait_for_alt_mode) in archive drivers/built-in.a
>>> referenced by dc_link.c
>>> gpu/drm/amd/display/dc/core/dc_link.o:(wait_for_alt_mode) in archive drivers/built-in.a

time_taken_in_ns is of type unsigned long long so we need to use div_u64
to avoid this error.

Fixes: b5b1f455 ("drm/amd/display: Enable type C hotplug")
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/core/dc_link.c

@@ -721,7 +721,7 @@ bool wait_for_alt_mode(struct dc_link *link)
 			time_taken_in_ns = dm_get_elapse_time_in_ns(
 				link->ctx, finish_timestamp, enter_timestamp);
 			DC_LOG_WARNING("Alt mode entered finished after %llu ms\n",
-				       time_taken_in_ns / 1000000);
+				       div_u64(time_taken_in_ns, 1000000));
 			return true;
 		}
 
@@ -730,7 +730,7 @@ bool wait_for_alt_mode(struct dc_link *link)
 	time_taken_in_ns = dm_get_elapse_time_in_ns(link->ctx, finish_timestamp,
 						    enter_timestamp);
 	DC_LOG_WARNING("Alt mode has timed out after %llu ms\n",
-			time_taken_in_ns / 1000000);
+			div_u64(time_taken_in_ns, 1000000));
 	return false;
 }