arm64: Convert bool ARM64_x_LEVELS to int ARM64_PGTABLE_LEVELS

Rather than having several Kconfig options, define int
ARM64_PGTABLE_LEVELS which will be also useful in converting some of the
pgtable macros.

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

diff --cc arch/arm64/Kconfig
Simple merge

diff --cc arch/arm64/include/asm/page.h
Simple merge

diff --cc arch/arm64/include/asm/pgalloc.h
Simple merge

diff --cc arch/arm64/include/asm/pgtable-hwdef.h
Simple merge

diff --cc arch/arm64/include/asm/pgtable.h
Simple merge

diff --cc arch/arm64/include/asm/tlb.h
Simple merge

diff --cc arch/arm64/kernel/head.S
Simple merge

diff --cc arch/arm64/mm/ioremap.c
Simple merge