sparse: Rename the file and header

The Android sparse image format is currently supported through a file
called aboot, which isn't really such a great name, since the sparse image
format is only used for transferring data with fastboot.

Rename the file and header to a file called "sparse", which also makes it
consistent with the header defining the image structures.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Tom Rini <trini@konsulko.com>

common/Makefile

@@ -277,7 +277,7 @@ obj-y += stdio.o
 
 # This option is not just y/n - it can have a numeric value
 ifdef CONFIG_FASTBOOT_FLASH
-obj-y += aboot.o
+obj-y += image-sparse.o
 ifdef CONFIG_FASTBOOT_FLASH_MMC_DEV
 obj-y += fb_mmc.o
 endif