* Fix: watchdog timed out, if flash blank (0xFF) blocks

The current implementation of cfi_flash uses udelay to reset watchdog.
If several blocks are blank (0xff filled) the watchdog timed out.
The reason is, udelay is never called, if flash device is ready to fast.

e.g.
     mw.w $(copy_addr) FFFF 10000;cp.b $(copy_addr) 10880000 20000

     -> watchdog timed out

     mw.w $(copy_addr) 0000 10000;cp.b $(copy_addr) 10880000 20000

     -> watchdog not timed out

This patch adds an extra watchdog reset in front of flash ready check.

Signed-off-by: Jens Scharsig (BuS Elektronik) <esw@bus-elektronik.de>
Signed-off-by: Stefan Roese <sr@denx.de>