arm: plat-orion: use void __iomem pointers for time functions

The functions for time management now take void __iomem pointers, so
we remove the temporary "unsigned long" casts from the mach-*/common.c
files.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Tested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>