dra7xx: Always enable UART1 and UART3 in early_padconf

It is safe to always setup the pinmux for UART1 and UART3 to be used in
early_padconf and then if these pins are needed later on, they will be
re-muxed.  This allows us to drop the usage of CONFIG_CONS_INDEX here.

Cc: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Lokesh Vutla <lokeshvutla@ti.com>