x86/Kconfig: Turn off CONFIG_BLK_DEV_RAM

x86/Kconfig: Turn off CONFIG_BLK_DEV_RAM

The vast majority of systems either use initramfs or mount a
root filesystem directly from the kernel.  Distros have
defaulted to initramfs for years.  Only highly specialized
systems would use an actual filesystem-image initrd at this
point, and such systems don't rely on defconfig anyway.  Drop
initrd support (and specifically RAM block device support) from
the defconfigs.

Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/2521e983a63595cd7a331236d929577660f89c72.1346649518.git.josh@joshtriplett.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>