qnap_tsx1x_register_flash is only called by qnap_ts219_init and
qnap_ts41x_init which both live in .init.text, too.  So the move is OK.

This fixes the following warning in kirkwood_defconfig:
	WARNING: vmlinux.o(.text+0x9334): Section mismatch in reference from the function qnap_tsx1x_register_flash() to the variable .init.data:qnap_tsx1x_spi_slave_info
	The function qnap_tsx1x_register_flash() references
	the variable __initdata qnap_tsx1x_spi_slave_info.
	This is often because qnap_tsx1x_register_flash lacks a __initdata
	annotation or the annotation of qnap_tsx1x_spi_slave_info is wrong.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>