lib_arch/board.c: Move malloc initialization before flash_init()

lib_arch/board.c: Move malloc initialization before flash_init()

This patch moves the malloc initialization before calling flash_init().
Upcoming changes to the NOR FLASH common CFI driver with optional
MTD infrastructure and MTD concatenation support will call malloc().
And nothing really speaks against enabling malloc just a little earlier
in the boot stage. Some architectures already enable malloc before
calling flash_init() so they don't need any changes here.

Signed-off-by: Stefan Roese <[email protected]>
Cc: Wolfgang Denk <[email protected]>
Cc: Mike Frysinger <[email protected]>
Cc: Scott McNutt <[email protected]>
Cc: Shinya Kuribayashi <[email protected]>
Cc: Nobuhiro Iwamatsu <[email protected]>
Cc: Daniel Hellstrom <[email protected]>
Cc: Jean-Christophe PLAGNIOL-VILLARD <[email protected]>
Cc: John Rigby <[email protected]>