lpc32xx: remove surplus clock cycle in PL175 WAIT_OEN config

According to ARM PrimeCell PL175 documentation WAIT_OEN config value
is defined without any additional clocks added to the value set by a
client, the change fixes the wrong interface to WAIT_OEN config.

The change also touches a single user of LPC32xx EMC and corrects
configured "output enable delay" value on its side according to the
changed interface.

No functional change intended.

Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>