[ARM] kirkwood: fix section mismatch

kirkwood_timer_init() and kirkwood_pcie_setup() lack of __init which
causes following warnings:

WARNING: vmlinux.o(.text+0x9568): Section mismatch in reference from
the function kirkwood_timer_init() to the function
.init.text:kirkwood_find_tclk()
The function kirkwood_timer_init() references
the function __init kirkwood_find_tclk().
This is often because kirkwood_timer_init lacks a __init
annotation or the annotation of kirkwood_find_tclk is wrong.

WARNING: vmlinux.o(.text+0x979c): Section mismatch in reference from
the function kirkwood_pcie_setup() to the function
.init.text:orion_pcie_setup()
The function kirkwood_pcie_setup() references
the function __init orion_pcie_setup().
This is often because kirkwood_pcie_setup lacks a __init
annotation or the annotation of orion_pcie_setup is wrong.

Signed-off-by: lijie <eltshanli@gmail.com>
Signed-off-by: Nicolas Pitre <nico@fluxnic.net>