serial/ns16550: Move RW objects from driver config to driver context.
serial/ns16550: Move RW objects from driver config to driver context.

PCI enumeration modifies pci_dev and port at driver initialization,
these objects move from config_info to driver_data in preparation for
config_info becoming const.

This driver shares a unified uart configuration structure with other
uart device drivers.  The structure uses 'union' and the preprocessor
to customize the structure to the drivers specific requirement.  There
appears to be no compelling reason why all the uart drivers should
share the same (customized) config_info structure.  In order to
re-organize the structure for this driver to get config_info const, an
ns16550 specific config structure is defined and the driver switched
over from the generic uart_config.

Change-Id: I31932d811f623a9370b69903114ae97b15d65886
Signed-off-by: Marcus Shawcroft <cf6354583ee83038f2010cbcbe1b1f2adb85107d@arm.com>

zephyriot/zephyr,GiulianoFranchetto/zephyr,ldts/zephyr,bigdinotech/zephyr,runchip/zephyr-cc3200,finikorg/zephyr,Vudentz/zephyr,runchip/zephyr-cc3220,rsalveti/zephyr,sharronliu/zephyr,nashif/zephyr,pklazy/zephyr,rsalveti/zephyr,runchip/zephyr-cc3200,aceofall/zephyr-iotos,zephyrproject-rtos/zephyr,GiulianoFranchetto/zephyr,holtmann/zephyr,bigdinotech/zephyr,tidyjiang8/zephyr-doc,Vudentz/zephyr,aceofall/zephyr-iotos,tidyjiang8/zephyr-doc,fbsder/zephyr,nashif/zephyr,fractalclone/zephyr-riscv,punitvara/zephyr,explora26/zephyr,erwango/zephyr,runchip/zephyr-cc3220,ldts/zephyr,explora26/zephyr,runchip/zephyr-cc3220,erwango/zephyr,nashif/zephyr,galak/zephyr,punitvara/zephyr,zephyriot/zephyr,fbsder/zephyr,aceofall/zephyr-iotos,pklazy/zephyr,pklazy/zephyr,fbsder/zephyr,fractalclone/zephyr-riscv,galak/zephyr,bigdinotech/zephyr,kraj/zephyr,Vudentz/zephyr,runchip/zephyr-cc3200,zephyrproject-rtos/zephyr,punitvara/zephyr,sharronliu/zephyr,ldts/zephyr,fractalclone/zephyr-riscv,zephyrproject-rtos/zephyr,finikorg/zephyr,explora26/zephyr,runchip/zephyr-cc3200,fractalclone/zephyr-riscv,GiulianoFranchetto/zephyr,bboozzoo/zephyr,zephyriot/zephyr,aceofall/zephyr-iotos,tidyjiang8/zephyr-doc,finikorg/zephyr,bboozzoo/zephyr,GiulianoFranchetto/zephyr,mbolivar/zephyr,Vudentz/zephyr,sharronliu/zephyr,rsalveti/zephyr,kraj/zephyr,sharronliu/zephyr,rsalveti/zephyr,erwango/zephyr,bboozzoo/zephyr,aceofall/zephyr-iotos,fractalclone/zephyr-riscv,finikorg/zephyr,erwango/zephyr,GiulianoFranchetto/zephyr,holtmann/zephyr,mbolivar/zephyr,holtmann/zephyr,zephyriot/zephyr,explora26/zephyr,bigdinotech/zephyr,fbsder/zephyr,Vudentz/zephyr,pklazy/zephyr,holtmann/zephyr,nashif/zephyr,punitvara/zephyr,bboozzoo/zephyr,pklazy/zephyr,sharronliu/zephyr,galak/zephyr,finikorg/zephyr,zephyriot/zephyr,ldts/zephyr,bboozzoo/zephyr,tidyjiang8/zephyr-doc,kraj/zephyr,explora26/zephyr,galak/zephyr,erwango/zephyr,zephyrproject-rtos/zephyr,ldts/zephyr,rsalveti/zephyr,mbolivar/zephyr,runchip/zephyr-cc3200,holtmann/zephyr,galak/zephyr,punitvara/zephyr,tidyjiang8/zephyr-doc,runchip/zephyr-cc3220,nashif/zephyr,kraj/zephyr,bigdinotech/zephyr,zephyrproject-rtos/zephyr,mbolivar/zephyr,fbsder/zephyr,mbolivar/zephyr,Vudentz/zephyr,kraj/zephyr,runchip/zephyr-cc3220