irqchip: gic-pm: Remove redundant error log of clock bulk

There is error log in clk_bulk_prepare/enable()

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/1617937474-24630-1-git-send-email-chunfeng.yun@mediatek.com