ARC: build: disallow invalid PAE40 + 4K page config

The config option being built was
| CONFIG_ARC_MMU_V4=y
| CONFIG_ARC_PAGE_SIZE_4K=y
| CONFIG_HIGHMEM=y
| CONFIG_ARC_HAS_PAE40=y

This was hitting a BUILD_BUG_ON() since a 4K page can't hoist 1k, 8-byte
PTE entries (8 byte due to PAE40). BUILD_BUG_ON() is a good last ditch
resort, but such a config needs to be disallowed explicitly in Kconfig.

Side-note: the actual fix is single liner dependency, but while at it
cleaned out a few things:
 - 4K dependency on MMU v3 or v4 is always true, since 288ff7de
   ("ARC: retire MMUv1 and MMUv2 support")
 - PAE40 dependency in on MMU ver not really ISA, although that follows
   eventually.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202409160223.xydgucbY-lkp@intel.com/


Signed-off-by: Vineet Gupta <vgupta@kernel.org>