init: remove deprecated "load_ramdisk" and "prompt_ramdisk" command line parameters

init: remove deprecated "load_ramdisk" and "prompt_ramdisk" command line parameters

...which do nothing. They were deprecated (in documentation) in
6b99e6e6aa62 ("Documentation/admin-guide: blockdev/ramdisk: remove use of
"rdev"") in 2020 and in kernel messages in c8376994c86c ("initrd: remove
support for multiple floppies") in 2020.

Signed-off-by: Askar Safin <safinaskar@gmail.com>
Link: https://patch.msgid.link/20251119222407.3333257-2-safinaskar@gmail.com
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>