arm64: Add missing Falkor part number for branch predictor hardening

References to CPU part number MIDR_QCOM_FALKOR were dropped from the
mailing list patch due to mainline/arm64 branch dependency. So this
patch adds the missing part number.

Fixes: ec82b567

 ("arm64: Implement branch predictor hardening for Falkor")
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Shanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>