ARM: pxa: remove incorrect __init annotation on pxa27x_set_pwrmode

The z2 machine calls pxa27x_set_pwrmode() in order to power off
the machine, but this function gets discarded early at boot because
it is marked __init, as pointed out by kbuild:

WARNING: vmlinux.o(.text+0x145c4): Section mismatch in reference from the function z2_power_off() to the function .init.text:pxa27x_set_pwrmode()
The function z2_power_off() references
the function __init pxa27x_set_pwrmode().
This is often because z2_power_off lacks a __init
annotation or the annotation of pxa27x_set_pwrmode is wrong.

This removes the __init section modifier to fix rebooting and the
build error.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: ba4a90a6 ("ARM: pxa/z2: fix building error of pxa27x_cpu_suspend() no longer available")
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>