mtd: replace MTDDEBUG() with pr_debug()

mtd: replace MTDDEBUG() with pr_debug()

In old days, the MTD subsystem in Linux had debug facility like
DEBUG(MTD_DEBUG_LEVEL1, ...).

They were all replaced with pr_debug() until Linux 3.2.  See Linux
commit 289c05222172 ("mtd: replace DEBUG() with pr_debug()").

U-Boot still uses similar macros.  Covert all of them for easier sync.

Done with the help of Coccinelle.

The semantic patch I used is as follows:

// <smpl>
@@
expression e1, e2;
@@
-MTDDEBUG(e1, e2)
+pr_debug(e2)
@@
expression e1, e2;
@@
-MTDDEBUG(e1, e2,
+pr_debug(e2,
 ...)
// </smpl>

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>