ppc/pnv: Fix fatal bug on 32-bit hosts

ppc/pnv: Fix fatal bug on 32-bit hosts

If the pnv machine type is compiled on a 32-bit host, the unsigned long
(host) type is 32-bit.  This means that the hweight_long() used to
calculate the number of allowed cores only considers the low 32 bits of
the cores_mask variable, and can thus return 0 in some circumstances.

This corrects the bug.

Signed-off-by: David Gibson <[email protected]>
Suggested-by: Richard Henderson <[email protected]>
[clg: replaced hweight_long() by ctpop64() ]
Signed-off-by: Cédric Le Goater <[email protected]>
Signed-off-by: David Gibson <[email protected]>