rsi: fix comment syntax in file headers

The opening comment mark '/**' is used for highlighting the beginning of
kernel-doc comments.
There are some files in drivers/net/wireless/rsi which follow this syntax
in their file headers, i.e. start with '/**' like comments, which causes
unexpected warnings from kernel-doc.

E.g., running scripts/kernel-doc -none on drivers/net/wireless/rsi/rsi_coex.h
causes this warning:
"warning: wrong kernel-doc identifier on line:
 * Copyright (c) 2018 Redpine Signals Inc."

Similarly for other files too.

Provide a simple fix by replacing such occurrences with general comment
format, i.e., "/*", to prevent kernel-doc from parsing it.

Signed-off-by: Aditya Srivastava <yashsri421@gmail.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20210315173259.8757-1-yashsri421@gmail.com