perf arm64: Add missing -I for tools/arch/arm64/include/ to find asm/sysreg.h when building arm_spe.h

This cures a current problem where tools/perf/util/arm-spe.c isn't
finding a ARM64 specific asm header, so lets add it for now to make
progress.

Adding a .o specific rule seems clunky, lets try and find if this is
really the right solution.
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reported-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: James Morse <james.morse@arm.com>
Link: https://lore.kernel.org/lkml/20220811124825.GA868014@leoy-huanghe.lanSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>