drivers: replace page size definitions with function

drivers: replace page size definitions with function

The page size is often retrieved from the macro PAGE_SIZE.
If PAGE_SIZE is not defined, it is either using hard coded default,
or getting the system value from the UNIX-only function sysconf().

Such definitions are replaced with the generic function
rte_mem_page_size() defined for each supported OS.

Removing PAGE_SIZE definitions will fix dlb drivers for musl libc,
because #ifdef checks were missing, causing redefinition errors.

Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
Acked-by: Andrew Boyer <aboyer@pensando.io>
Acked-by: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>
Acked-by: David Marchand <david.marchand@redhat.com>
Acked-by: Timothy McDaniel <timothy.mcdaniel@intel.com>