ARM: bcm283x: Reduce register ranges for UART, SPI and I2C

The assigned register ranges for UART, SPI and I2C were too wasteful.
In order to avoid overlapping with the new functions on BCM2711
reduce the ranges.

Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Acked-by: Eric Anholt <eric@anholt.net>