Replace the hardcoded 4096 value with the PAGE_SIZE macro.
Converted a few decimal numbers to readable hex numbers.

Use of PAGE_SIZE required a small change to page.h
to allow PAGE_SIZE to be used from assembler/linker scripts.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>