ARM: 5673/1: U300 fix initsection compile warning

The u300_init_check_chip() function was not properly tagged with
the __init macro and provided a initsection mismatch on
compilation.

Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>