treewide: unify the linker symbol reference format

treewide: unify the linker symbol reference format

Now all linker symbols are declared as type char[]. Though we can
reference the address via both the array name 'var' and its address
'&var'. It's better to unify them to avoid confusing developers.
This patch converts all '&var' linker symbol refrences to the most
commonly used format 'var'.

Signed-off-by: Shiji Yang <yangshiji66@outlook.com>
Reviewed-by: Tom Rini <trini@konsulko.com>