Cleanup for user headers, as noted:

asm-sh/page.h requires asm-generic/memory_model.h, which does not exist in exported headers
asm-sh/ptrace.h requires asm/ubc.h, which does not exist in exported headers
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>