linux-imx

s390/mem_detect: provide single get_mem_detect_end

get_mem_detect_end is already used in couple of places with potential
to be utilized in more cases. Provide single get_mem_detect_end
implementation in asm/mem_detect.h to be used by kasan and startup code.

Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>