firmware: vpd: Drop __iomem usage for memremap() memory

memremap() doesn't return an iomem pointer, so we can just use memcpy()
and drop the __iomem annotation here. This silences a sparse warning.

Cc: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Anton Vasilyev <vasilyev@ispras.ru>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>