arm64: Remove asm/pgtable-*level-hwdef.h files

The macros in these files can easily be computed based on PAGE_SHIFT and
VA_BITS, so just remove them and add the corresponding macros to
asm/pgtable-hwdef.h

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Jungseok Lee <jungseoklee85@gmail.com>