Fix typos in /Documentation : 'U-Z'

This patch fixes typos in various Documentation txts. The patch addresses some
+words starting with the letters 'U-Z'.

Looks like I made it through the alphabet...just in time to start over again
+too!  Maybe I can fit more profound fixes into the next round...?  Time will
+tell. :)

Signed-off-by: Matt LaPlante <kernel1@cyberdogtech.com>
Acked-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
diff --git a/Documentation/eisa.txt b/Documentation/eisa.txt
index 6a099ed..60e361b 100644
--- a/Documentation/eisa.txt
+++ b/Documentation/eisa.txt
@@ -62,7 +62,7 @@
 bus_base_addr : slot 0 address on this bus
 slots	      : max slot number to probe
 force_probe   : Probe even when slot 0 is empty (no EISA mainboard)
-dma_mask      : Default DMA mask. Usualy the bridge device dma_mask.
+dma_mask      : Default DMA mask. Usually the bridge device dma_mask.
 bus_nr	      : unique bus id, set by eisa_root_register
 
 ** Driver :