iichid(4): Do not send packets read in interrupt handler to hidbus

if no hidbus and hidbus clients were attached and opened by users.

iichid(4) enables interrupts before hidbus is attached and sending
packets to it at this time leads to panic at boot time.

Fixes: daa098cc37b9 ("Wait for RESET command response while attaching")

Tested by: dch
PR: 286045
MFC with: daa098cc37b9