Revert "powerpc: fix regression in arch_initr_trap()"

With the changes in commit 588efcdd72fc ("powerpc: Don't use relative
include for config.h in global_data.h") fixing the root of the problem,
we no longer need this re-inclusion.

This reverts commit f6c0d365.

Cc: Matt Merhar <mattmerhar@protonmail.com>
Signed-off-by: Tom Rini <trini@konsulko.com>