INSTALL kernel exceeds 5MB for zaurus

[Rin Okuyama <rokuyama%rk.phys.keio.ac.jp@localhost>]

Build fails for zaurus because the INSTALL kernel exceeds 5MB:

  http://releng.netbsd.org/builds/HEAD/201702072140Z/

I've found that there is extra space in the ramdisk. Is it OK to reduce
the ramdisk by, for example, 80KB (2256 -> 2176KB)? Then, the INSTALL
kernel fits within 5MB.

Besides, I propose for the kernel side,

  - drop DKWEDGE_METHOD_APPLE (0.4KB)

and for the ramdisk side,

  - drop FFS_EI and Apple UFS supports from fsck_ffs and newfs (13.4KB)
  - drop shutdown (3.5KB)

Then, we can save 17.3KB of the INSTALL kernel. Extra spaces for the
main kernel and ramdisk become 62.5KB and 232KB, respectively.

Thanks,
rin