Fix obvious typo in microblaze.opt

[Philipp Thomas]

I just just checked this in under the obvious bug fix rule:

2011-01-04  Philipp Thomas <pth@suse.de>

	* config/microblaze/microblaze.opt (mxl-float-convert): Fix
	obvious typo.

Index: config/microblaze/microblaze.opt
===================================================================
--- config/microblaze/microblaze.opt	(Revision 168463)
+++ config/microblaze/microblaze.opt	(Arbeitskopie)
@@ -74,7 +74,7 @@
 
 mxl-float-convert
 Target Mask(FLOAT_CONVERT)
-Use hardware floating point converstion instructions
+Use hardware floating point conversion instructions
 
 mxl-float-sqrt
 Target Mask(FLOAT_SQRT)