[sdmmc] Fix Sandisk U1 fast power cycle

Some Sandisk U1 sd cards do not behave nicely if they power cycle too fast. A min 100ms wait, is enough to mitigate that.

Fortunately, because of how the code paths are structured, this was never hit.

bootloader/config/config.c

@@ -45,6 +45,7 @@ void set_default_configuration()
 	h_cfg.autonogc = 1;
 	h_cfg.sept_run = EMC(EMC_SCRATCH0) & EMC_SEPT_RUN;
 	h_cfg.rcm_patched = true;
+	h_cfg.sd_timeoff = 0;
 }
 
 int create_config_entry()