ide: icside: remove incorrect initconst annotation

The icside_probe function can be called for hotplugged devices, so
its reference to the __initconst icside_v6_port_info variable
may be invalid, as Kbuild points out:

WARNING: drivers/ide/icside.o(.text+0x338): Section mismatch in reference from the function icside_probe()
 to the (unknown reference) .init.rodata:(unknown)

Interestingly, this problem only shows up with clang but not
with gcc, which optimizes out the __initconst variable.

This removes the incorrect annotation.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>