serial: qcom-geni: Make UART port count configurable via Kconfig

serial: qcom-geni: Make UART port count configurable via Kconfig

Replace the hardcoded GENI_UART_PORTS macro with a new Kconfig option
SERIAL_QCOM_GENI_UART_PORTS to allow platforms to configure the maximum
number of UART ports supported by the driver at build time.

This improves flexibility for platforms that require more than the
previously fixed number of UART ports, and avoids unnecessary allocation
for unused ports.

Signed-off-by: Zong Jiang <quic_zongjian@quicinc.com>
Link: https://lore.kernel.org/r/20250812054819.3748649-3-quic_zongjian@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>