powerpc/vdso: Replace vdso_base by vdso

All other architectures but s390 use a void pointer named 'vdso'
to reference the VDSO mapping.

In a following patch, the VDSO data page will be put in front of
text, vdso_base will then not anymore point to VDSO text.

To avoid confusion between vdso_base and VDSO text, rename vdso_base
into vdso and make it a void __user *.

Signed-off-by: Christophe Leroy <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/8e6cefe474aa4ceba028abb729485cd46c140990.1601197618.git.christophe.leroy@csgroup.eu
13 files changed