xen/arm: gic-v3: No need to sort the Redistributor regions

xen/arm: gic-v3: No need to sort the Redistributor regions

The sorting was required by the vGIC emulation until commit
9b9d51e98edb8c5c731e2d06dfad3633053d88a4 "xen/arm: vgic-v3:
Correctly retrieve the vCPU associated to a re-distributor".

Furthermore, the code is buggy because both local variables 'l' and 'r'
point to the same region.

So drop the code which sort the Redistributors array.

Reported-by: Shanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: Julien Grall <julien.grall@arm.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>