OMAP2+: remove unused UART base addresses from omap_globals

Now that omap_hwmod + omap_device is used for OMAP UART device and
driver code, we no longer need the UART physical addresses in
omap_globals.

Note that the #defines for the base addresses are still left in
<plat/serial.h> since they are used by DEBUG_LL and uncompress code.

Build tested for OMAP1 (omap1_defconfig) and OMAP2+ (omap2plus_defconfig)

Signed-off-by: Kevin Hilman <khilman@ti.com>