sparc64: vdso: Move hardware counter read into header

sparc64: vdso: Move hardware counter read into header

The generic vDSO libraries expected the architecture glue around hardware
counter reading in asm/vdso/gettimeofday.h. To prepare the adoption of the
generic library, move the existing functions there.

While at it, perform some trivial alignment with the generic vDSO library:
* Drop 'notrace', as the functions are __always_inline anyways
* Use the same parameter types
* Use the same function names

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Tested-by: Andreas Larsson <andreas@gaisler.com>
Reviewed-by: Andreas Larsson <andreas@gaisler.com>
Acked-by: Andreas Larsson <andreas@gaisler.com>
Link: https://patch.msgid.link/20260304-vdso-sparc64-generic-2-v6-7-d8eb3b0e1410@linutronix.de