insane.bbclass: Fix ELF bitsize comparison

Fix the way the ELF size is compared to ensure that incorrectly
sized ELF binaries are captured during the file scan.

lib/oe/qa.py is changed to accept a bitsize as a parameter.  Instead
of previously defining true/false, it now takes "0" undefined, "32"
32-bit, and "64" 64-bit as the size argument.  This allows us to
preserve existing behavior of only loading one ELF type, while
allowing the function to be able to discover the size on it's own.

Signed-off-by: Mark Hatle <mark.hatle@windriver.com>