arm64/mm: Directly use TTBRx_EL1_CnP

arm64/mm: Directly use TTBRx_EL1_CnP

Replace all TTBR_CNP_BIT macro instances with TTBRx_EL1_CNP_BIT which
is a standard field from tools sysreg format. Drop the now redundant
custom macro TTBR_CNP_BIT. No functional change.

Cc: Will Deacon <will@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Oliver Upton <oupton@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: kvmarm@lists.linux.dev
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>