ARM: zImage: make sure the stack is 64-bit aligned

ARM: zImage: make sure the stack is 64-bit aligned

BugLink: http://bugs.launchpad.net/bugs/788691

commit 3bd2cbb95543acf44fe123eb9f038de54e655eb4 upstream.

With ARMv5+ and EABI, the compiler expects a 64-bit aligned stack so
instructions like STRD and LDRD can be used.  Without this, mysterious
boot failures were seen semi randomly with the LZMA decompressor.

While at it, let's align .bss as well.

Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Steve Conklin <sconklin@canonical.com>