ARM: OMAP: SX1: remove check for CONFIG_SX1_OLD_FLASH

A check for CONFIG_SX1_OLD_FLASH was added in v2.6.24. But the related
Kconfig symbol was never part of the tree. So we can remove some dead
code.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Tony Lindgren <tony@atomide.com>