default or selected kernelversion does not have config value CONFIG_OMAP2_DSS_SLEEP_BEFORE_RESET.
Result is shown for kernelversion 5.6.18

Sleep 50ms before DSS reset


Linux Kernel Configuration
└─>Device Drivers
└─>Graphics support
└─>OMAP2+ Display Subsystem support (EXPERIMENTAL)
└─>Sleep 50ms before DSS reset
In linux kernel since version 3 (release Date: 2011-07-21)  
For some unknown reason we may get SYNC_LOST errors from the display
subsystem at initialization time if we don't sleep before resetting
the DSS. See the source (dss.c) for more comments.

However, 50ms is quite long time to sleep, and with some
configurations the SYNC_LOST may never happen, so the sleep can
be disabled here.