flash/nor/rp2040: fix flash erase timeout

flash/nor/rp2040: fix flash erase timeout

SPI flash erase often takes longer than the fixed timeout 3 seconds.

Introduce a configurable timeout_ms parameter to rp2040_call_rom_func().
Compute the erase timeout from the number of blocks to be erased.

While on it make the timeouts shorter for connect flash, flush cache and
enter/exit xip (1 second is enough).

Change-Id: I552bfa317ee17064de3a54ec2f0c63e84ba87222
Signed-off-by: Tomas Vanek <vanekt@fbl.cz>
Reviewed-on: https://review.openocd.org/c/openocd/+/7214
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-by: Jonathan Bell <jonathan@raspberrypi.com>