lscpu: add {32,64}-bit CPU modes detection

lscpu: add {32,64}-bit CPU modes detection

This patch add "CPU op-mode(s):" field that prints all supported CPU
operation modes. The field is based on CPU flags:

	rm (real mode)          16-bit
	tm (transparent mode)   32-bit
	lm (long mode)          64-bit

Example:

	$ lscpu
	Architecture:          x86_64
	CPU op-mode(s):        32-bit, 64-bit
	CPU(s):                2
	Thread(s) per core:    1
	Core(s) per socket:    2
	CPU socket(s):         1
	NUMA node(s):          1
	Vendor ID:             GenuineIntel
	CPU family:            6
	Model:                 15
	Stepping:              11
	CPU MHz:               1600.000
	Virtualization:        VT-x
	L1d cache:             32K
	L1i cache:             32K
	L2 cache:              4096K

Signed-off-by: Karel Zak <kzak@redhat.com>