ARM: omap2+: hwmod: fix potential NULL pointer access

stable inclusion
from stable-5.10.58
commit 3d7d2d2b069bdc736d491cb989d3d00483e4e9e6
bugzilla: 176984 https://gitee.com/openeuler/kernel/issues/I4E2P4

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=3d7d2d2b069bdc736d491cb989d3d00483e4e9e6



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commit b070f9ca upstream.

omap_hwmod_get_pwrdm() may access a NULL clk_hw pointer in some failure
cases. Add a check for the case and bail out gracely if this happens.

Reported-by: Dan Murphy <dmurphy@ti.com>
Signed-off-by: Tero Kristo <t-kristo@ti.com>
Cc: stable@vger.kernel.org # v5.10+
Signed-off-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Chen Jun <chenjun102@huawei.com>
Acked-by: Weilong Chen <chenweilong@huawei.com>
Signed-off-by: Chen Jun <chenjun102@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>