Use 'Primary' instead of 'Current' for flash sides

When queried libflash will return the 'first' flash side (ie. the one
with the lowest TOC address), however we label this the 'Current' side
which is incorrect if the machine has booted from the alternate side.

A future fix will inlcude additional platform logic to determine which
flash side is current; in the interim label the first flash side as
'Primary' instead of 'Current'.

Signed-off-by: Sam Mendoza-Jonas <sam@mendozajonas.com>