warp7, pic32mzdask: Remove SYS_FDT_ADDR/SYS_ENV_ADDR from CONFIG namespace

In the case of CONFIG_SYS_FDT_ADDR this was being used to modify the
default value of fdt_addr / fdt_addr_r, which is not something to expose
in this manner and is not otherwise done.  The case of SYS_ENV_ADDR is
similar but only done on the pic32mzdask platform, for scriptaddr.

Signed-off-by: Tom Rini <trini@konsulko.com>