4xx: Fix compilation warnings and MQ registers dump in SPD DDR2 code

This patch fixes printf format string compilation warnings in several
debug statements. It also fixes the dump of DDR controller MQ registers
found on some 44x and 46x platforms. The current register dump code
uses incorrect DCRs to access these registers.

Signed-off-by: Felix Radensky <felix@embedded-sol.com>
Signed-off-by: Stefan Roese <sr@denx.de>