cmd: ubifs: Remove select for non-existent option

There is no 'config CRC32', remove the select that was attempting to use
it.

Reported-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Chris Packham <judge.packham@gmail.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
diff --git a/cmd/Kconfig b/cmd/Kconfig
index 4e11e0f..fd1beb0 100644
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -1933,7 +1933,6 @@
 
 config CMD_UBI
 	tristate "Enable UBI - Unsorted block images commands"
-	select CRC32
 	select MTD_UBI
 	help
 	  UBI is a software layer above MTD layer which admits use of LVM-like
@@ -1949,7 +1948,6 @@
 	tristate "Enable UBIFS - Unsorted block images filesystem commands"
 	depends on CMD_UBI
 	default y if CMD_UBI
-	select CRC32
 	select LZO
 	help
 	  UBIFS is a file system for flash devices which works on top of UBI.