[SPARC32]: Remove superfluous 'kernel_end' alignment on sun4c.

In sun4c_init_clean_mmu(), aligning 'kernel_end' using
SUN4C_REAL_PGDIR_ALIGN() is unnecessary since the caller
does this already.

In sun4c_paging_init(), 4 page sizes of "fluff" were added
to the address of &end.  This was necessary a long time ago
when sparc32 would allocate some early data structures
by carving out memory chunks after &end but that no longer
occurs.

Signed-off-by: Mark Fortescue <mark@mtfhpc.demon.co.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>