arm64: remove ptrauth_keys_install_kernel sync arg

arm64: remove ptrauth_keys_install_kernel sync arg

The 'sync' argument to ptrauth_keys_install_kernel macro is somewhat
opaque at callsites, so instead lets have regular and _nosync variants
of the macro to make this a little more obvious.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Amit Daniel Kachhap <amit.kachhap@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200423101606.37601-2-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>