drivers: espi: xec: Ensure all eSPI VW are transmitted

When a eSPI slave needs to send back-to-back packets
updating status signal need to guarantee both status
reach the eSPI host, i.e. SCI=0 followed by SCI=1.
This change guarantees both packets are transmitted
over esSPI bus.

Allow to map eSPI host logical UART to a soc UART.

Signed-off-by: Jose Alberto Meza <jose.a.meza.arellano@intel.com>