mmc: Separate "mmc swrite" from fastboot

Introduce CONFIG_IMAGE_SPARSE and CONFIG_CMD_MMC_SWRITE so the "mmc
swrite" command is separated from the fastboot code.

Move image-sparse from common to lib so it's clear it's library code.

Rename CONFIG_FASTBOOT_FLASH_FILLBUF_SIZE to CONFIG_IMAGE_SPARSE_FILLBUF_SIZE
and migrate it to Kconfig.

Signed-off-by: Alex Kiernan <alex.kiernan@gmail.com>
Acked-by: Jassi Brar <jaswinder.singh@linaro.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/lib/Kconfig b/lib/Kconfig
index 1590f7a..15c6a52 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -61,6 +61,17 @@
 config TPL_STRTO
 	bool
 
+config IMAGE_SPARSE
+	bool
+
+config IMAGE_SPARSE_FILLBUF_SIZE
+	hex "Android sparse image CHUNK_TYPE_FILL buffer size"
+	default 0x80000
+	depends on IMAGE_SPARSE
+	help
+	  Set the size of the fill buffer used when processing CHUNK_TYPE_FILL
+	  chunks.
+
 config USE_PRIVATE_LIBGCC
 	bool "Use private libgcc"
 	depends on HAVE_PRIVATE_LIBGCC