ARM: 7416/1: LPAE: Remove unused L_PTE_(BUFFERABLE|CACHEABLE) macros

These have already been removed from the classic MMU in favour of
L_PTE_MT_* macros.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>