documentation: remove references to cpu_*_map.

This has been obsolescent for a while, fix documentation and
misc comments.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
diff --git a/arch/mips/pmc-sierra/yosemite/smp.c b/arch/mips/pmc-sierra/yosemite/smp.c
index 00a0d2e..b71fae2 100644
--- a/arch/mips/pmc-sierra/yosemite/smp.c
+++ b/arch/mips/pmc-sierra/yosemite/smp.c
@@ -146,7 +146,7 @@
 }
 
 /*
- * Detect available CPUs, populate cpu_possible_map before smp_init
+ * Detect available CPUs, populate cpu_possible_mask before smp_init
  *
  * We don't want to start the secondary CPU yet nor do we have a nice probing
  * feature in PMON so we just assume presence of the secondary core.