[PATCH][PPC32] fix locking bugs in mv64x60 code

[Mark A. Greer]

[Original patch slightly edited by mgreer]

This patch fixes 2 SMP deadlocks. The first is that mv64x60_read() was 
returning before the unlock. The second was mv64x60_modify() locks the spin 
lock and calls mv64x60_read() and mv64x60_write() which also lock the same spin lock.

Please apply.

Signed-Off-By: Brian Waite <waite at skycomputers.com>
Signed-off-by: Mark A. Greer <mgreer at mvista.com>