hw/misc/bcm2835_property: Restrict scope of start_num, number, otp_row

hw/misc/bcm2835_property: Restrict scope of start_num, number, otp_row

In the long function bcm2835_property_mbox_push(), the variables
start_num, number and otp_row are used only in the four cases which
access OTP data, and their uses don't overlap with each other.

Make these variables have scope restricted to the cases where they're
used, so it's easier to read each individual case without having to
cross-refer up to the variable declaration at the top of the function
and check whether the variable is also used later in the loop.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-id: 20240723131029.1159908-4-peter.maydell@linaro.org