cassini: use request_firmware

Firmware blob looks like this...
        __le16 load_address
        unsigned char data[]

[akpm@linux-foundation.org: include vmalloc.h]
Signed-off-by: Jaswinder Singh <jaswinder@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

WHENCE

@@ -339,3 +339,13 @@ Licence: Allegedly GPLv2+, but no source visible. Marked:
 Found in hex form in kernel source.
 
 --------------------------------------------------------------------------
+
+Driver: CASSINI - Sun Cassini
+
+File: sun/cassini.bin
+
+Licence: Unknown
+
+Found in hex form in kernel source.
+
+--------------------------------------------------------------------------