tcl/interface: universal config for all Raspberry Pi models

tcl/interface: universal config for all Raspberry Pi models

Speed calibration coeffs are computed from cpufreq/scaling_max_freq
and from the device-tree compatibility information.

Raspberry Pi linux offers /dev/gpiomem for non-root access
to the GPIO registers since ~2016.
Do not configure 'bcm2835gpio peripheral_base' as it is necessary
only if /dev/mem is used - it requires running OpenOCD as root
- it's a security risk so it should be avoided.

The configuration of the GPIO connector (40-pin header)
is factored out and ready to use in interface configuration
for other driver (e.g. linux gpiod).

Mark raspberrypi2-native.cfg as deprecated and redirect
it to raspberrypi-native.cfg

Change-Id: Icce856fb660b45374e94174da279feb51f529908
Signed-off-by: Tomas Vanek <vanekt@fbl.cz>
Reviewed-on: https://review.openocd.org/c/openocd/+/7264
Tested-by: jenkins
Reviewed-by: Jonathan Bell <jonathan@raspberrypi.com>
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>