serial: cpm_uart: Stop using fs_uart_id enum

Using an enum indirection to define numeric macros is
pointless. Directly use the wanted numeric value.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Link: https://lore.kernel.org/r/4772d2a21894db443fe42836421eb22206a334aa.1691068700.git.christophe.leroy@csgroup.eu


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>