x86: extend e820 ealy_res support 32bit - fix

use find_e820_area to find addess for new RAMDISK, instead of using ram blindly

also print out low ram and bootmap info

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>