ARM: fix the cockup in the previous patch

The intention in the previous patch was to only place the processor
tables in the .rodata section if big.Little was being built and we
wanted the branch target hardening, but instead (due to the way it
was tested) it ended up always placing the tables into the .rodata
section.

Although harmless, let's correct this anyway.

Fixes: 3a4d0c21 ("ARM: ensure that processor vtables is not lost after boot")
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>