docs(dracut.conf): regenerate_all not supported

The regenerate_all option is used before sourcing the configuration files.

man/dracut.conf.5.asc

@@ -257,11 +257,6 @@ Logging levels:
 *reproducible=*"__{yes|no}__"::
     Create reproducible images (default=no).
 
-*regenerate_all=*"__{yes|no}__"::
-    Regenerate all initramfs images at the default location with the kernel
-    versions found on the system. Additional parameters are passed through
-    (default=no).
-
 *noimageifnotneeded=*"__{yes|no}__"::
     Do not create an image in host-only mode, if no kernel driver is needed
     and no /etc/cmdline/*.conf will be generated into the initramfs