arm64: Add support for HIP09 Spectre-BHB mitigation

The HIP09 processor is vulnerable to the Spectre-BHB (Branch History
Buffer) attack, which can be exploited to leak information through
branch prediction side channels. This commit adds the MIDR of HIP09
to the list for software mitigation.

Signed-off-by: Jinqian Yang <yangjinqian1@huawei.com>
Link: https://lore.kernel.org/r/20250325141900.2057314-1-yangjinqian1@huawei.com


Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>