arm64: cputype: Add missing MIDR values for Cortex-A72 and Cortex-A75

From: Will Deacon <will.deacon@arm.com>

commit a65d219fe5dc7887fd5ca04c2ac3e9a34feb8dfc upstream.

Hook up MIDR values for the Cortex-A72 and Cortex-A75 CPUs, since they
will soon need MIDR matches for hardening the branch predictor.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com> [v4.9 backport]
Tested-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>