Eliminate kernel-doc warnings in drivers/pinctrl/aspeed by using
proper kernel-doc notation.

Fixes these kernel-doc warnings:

drivers/pinctrl/aspeed/pinmux-aspeed.c:61: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
    * Query the enabled or disabled state for a mux function's signal on a pin
drivers/pinctrl/aspeed/pinctrl-aspeed.c:135: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
    * Search for the signal expression needed to enable the pin's signal for the
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kernel test robot <lkp@intel.com>
Cc: Aditya Srivastava <yashsri421@gmail.com>
Cc: Andrew Jeffery <andrew@aj.id.au>
Cc: linux-aspeed@lists.ozlabs.org
Cc: openbmc@lists.ozlabs.org
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: linux-gpio@vger.kernel.org
Acked-by: Andrew Jeffery <andrew@aj.id.au>
Link: https://lore.kernel.org/r/20210723034840.8752-1-rdunlap@infradead.orgSigned-off-by: Linus Walleij <linus.walleij@linaro.org>