drm/amd: Fix UBSAN array-index-out-of-bounds for Polaris and Tonga

stable inclusion
from stable-v4.19.315
commit a63fd579e7b1c3a9ebd6e6c494d49b1b6cf5515e
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9RFE8
CVE: CVE-2023-52819

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=linux-4.19.y&id=a63fd579e7b1c3a9ebd6e6c494d49b1b6cf5515e

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[ Upstream commit 0f0e59075b5c22f1e871fbd508d6e4f495048356 ]

For pptable structs that use flexible array sizes, use flexible arrays.

Link: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2036742


Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Wenyu Huang <huangwenyu5@huawei.com>