PowerPC: Update dependencies on *SYS_MPC85XX_NO_RESETVEC

In 96699f09 ("powerpc: mpc85xx: Use binman to embed dtb inside
U-Boot") we introduce CONFIG_MPC85XX_HAVE_RESET_VECTOR and do so via
Kconfig. However, much later in de47ff53 ("Convert
CONFIG_SYS_MPC85XX_NO_RESETVEC to Kconfig") I converted the symbol that
is the inverse of this to Kconfig. This should have included a
dependency on the first symbol as they are logically opposite.

The dependency being missing lead to some platforms being broken at
runtime due to discarding the require reset vector.

Fixes: de47ff53 ("Convert CONFIG_SYS_MPC85XX_NO_RESETVEC to Kconfig")
Reported-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Tom Rini <trini@konsulko.com>
Tested-by: Pali Rohár <pali@kernel.org>