arm64: Fix size of __early_cpu_boot_status

commit 61cf61d81e326163ce1557ceccfca76e11d0e57c upstream.

__early_cpu_boot_status is of type long. Use quad
assembler directive to allocate proper size.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Arun KS <arunks@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>