pmapboot_enter simplication
- bootpage_alloc in asm becomes pmapboot_pagealloc in C
- PMAPBOOT_ENTER_NOBLOCK is removed as it's not used
- PMAPBOOT_ENTER_NOOVERWRITE is removed as it's now always on
- physpage_allocator argument is removed as it's always
  pmapboot_pagealloc
- Support for EARLYCONS without CONSADDR is removed so that the identity
  map for CONSADDR is always known.

For the assembly files:
2 files changed, 40 insertions(+), 89 deletions(-)

LGTM ryo

(skrll)