Add EM100 mode to Intel Firmware Descriptor tool

To avoid having two copies for every firmware descriptor (one for
EM100 use and one for real SPI flash use), add an EM100 mode to
ifdtool that allows to "dumb down" a fast image to the settings
required for the EM100 to work.

Change-Id: I0ed989f0a49316bc63d8627cb5d4bd988ae7a103
Signed-off-by: Stefan Reinauer <reinauer@google.com>
Reviewed-on: http://review.coreboot.org/1039
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

util/ifdtool/ifdtool.h

@@ -26,6 +26,15 @@ enum spi_frequency {
 	SPI_FREQUENCY_50MHZ = 4,
 };
 
+enum component_density {
+	COMPONENT_DENSITY_512KB = 0,
+	COMPONENT_DENSITY_1MB   = 1,
+	COMPONENT_DENSITY_2MB   = 2,
+	COMPONENT_DENSITY_4MB   = 3,
+	COMPONENT_DENSITY_8MB   = 4,
+	COMPONENT_DENSITY_16MB  = 5,
+};
+
 // flash descriptor
 typedef struct {
 	uint32_t flvalsig;