feat(nxp-drivers): add Linflex driver

This is a UART controller found on NXP automotive parts.
For instance: S32V, S32G and S32R.

Change-Id: Iff0dd0c379633ac0651e5db287537c87666b57d2
Signed-off-by: Bogdan Hamciuc <bogdan.hamciuc@nxp.com>
Signed-off-by: Ghennadi Procopciuc <ghennadi.procopciuc@nxp.com>