hw/arm/armsse: Make SRAM bank size configurable

hw/arm/armsse: Make SRAM bank size configurable

For the IoTKit the SRAM bank size is always 32K (15 bits); for the
SSE-200 this is a configurable parameter, which defaults to 32K but
can be changed when it is built into a particular SoC. For instance
the Musca-B1 board sets it to 128K (17 bits).

Make the bank size a QOM property. We follow the SSE-200 hardware in
naming the parameter SRAM_ADDR_WIDTH, which specifies the number of
address bits of a single SRAM bank.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190121185118.18550-11-peter.maydell@linaro.org