[ARM] qnap tsx1x: fix section mismatch

Fix the following warning :
WARNING: vmlinux.o(.text+0x95a0): Section mismatch in reference from the
function qnap_tsx1x_register_flash() to the (unknown reference) .init.data:(unknown)
The function qnap_tsx1x_register_flash() references
the (unknown reference) __initdata (unknown).
This is often because qnap_tsx1x_register_flash lacks a __initdata
annotation or the annotation of (unknown) is wrong.
Signed-off-by: Arnaud Patard <arnaud.patard@rtp-net.org>
Signed-off-by: Martin Michlmayr <tbm@cyrius.com>
Signed-off-by: Nicolas Pitre <nico@fluxnic.net>

arch/arm/mach-kirkwood/tsx1x-common.c

@@ -77,7 +77,7 @@ struct spi_board_info __initdata qnap_tsx1x_spi_slave_info[] = {
 	},
 };
 
-void qnap_tsx1x_register_flash(void)
+void __init qnap_tsx1x_register_flash(void)
 {
 	spi_register_board_info(qnap_tsx1x_spi_slave_info,
 				ARRAY_SIZE(qnap_tsx1x_spi_slave_info));