mailbox: qcom-ipcc: Support more IPCC instance

Since hardware is supporting multiple IPCC instance,
use ipcc_%d instead of ipcc as the irq name to support
in driver.

Signed-off-by: Huang Yiwei <quic_hyiwei@quicinc.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>