alpha: eliminate old-style function definitions

alpha: eliminate old-style function definitions

'make ARCH=alpha W=1' reports a couple of old-style function
definitions with missing parameter list, so fix those.

  arch/alpha/kernel/pc873xx.c: In function 'pc873xx_get_base':
  arch/alpha/kernel/pc873xx.c:16:21: warning: old-style function definition [-Wold-style-definition]
   16 | unsigned int __init pc873xx_get_base()

  arch/alpha/kernel/pc873xx.c: In function 'pc873xx_get_model':
  arch/alpha/kernel/pc873xx.c:21:14: warning: old-style function definition [-Wold-style-definition]
   21 | char *__init pc873xx_get_model()

Link: https://lkml.kernel.org/r/20210421061312.30097-1-rdunlap@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>