Add iMac5,2 to board_enable

When running coreboot everything works, while on vendor bios it fails
to erase anything until the 3th erase function of a SST25VF016B is
tried.

Change-Id: I5e4daaa67f98a47e237cd73962776da369c8f0b5
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/18943
Tested-by: build bot (Jenkins)
Reviewed-by: Nico Huber <nico.h@gmx.de>
1 file changed