HID: u2fzero: fix compiling error in u2fzero_probe()

There is one compiling error in u2fzero_probe()->u2fzero_init_hwrng(),
this is because HW_RANDOM is not set.

drivers/hid/hid-u2fzero.o: In function `u2fzero_probe':
hid-u2fzero.c:(.text+0xc70): undefined reference to `devm_hwrng_register'

Fixes: 42337b9d

("HID: add driver for U2F Zero built-in LED and RNG")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Mao Wenan <maowenan@huawei.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>