customizer: gpio_motors becomes ptz_gpio, with ptz_control naming the method (#140)

Completes the #227 PTZ env rename (majestic-webui#232, firmware#2341) in
the last place still writing the old name: the three customizer.sh files
carrying 'fw_setenv gpio_motors ...' now write ptz_gpio instead. The
gpio-motors utility reads ptz_gpio first and falls back to gpio_motors
since firmware#2341, and it is the only consumer of the variable anywhere
in the org, so the rename is mechanical.

Each device also gains 'fw_setenv ptz_control gpio' — not part of the
rename, but required by it: the WebUI dropped its auto-detection from a
bare pin list (unset ptz_control now means no PTZ, per flyrouter's ruling
on the same issue; majestic-webui#255). Without the method named, these
devices would keep their motors but lose their pads. In
t23_lite_jooan-a6m-u the pin line was commented out, so both new lines
are commented there too.

devices/ssc30kd_lite_cmcc-ds-ytj5301/general/overlay/usr/share/openipc/customizer.sh

@@ -37,7 +37,8 @@ cli -s .audio.speakerPin 11
 # Set motor and mmc
 #
 #fw_setenv gpio_mmc XX
-fw_setenv gpio_motors 111 112 113 114 59 60 8 9
+fw_setenv ptz_control gpio
+fw_setenv ptz_gpio 111 112 113 114 59 60 8 9
 #
 #
 #adduser viewer -s /bin/false -D -H ; echo viewer:123456 | chpasswd

devices/t23_lite_jooan-a6m-u/general/overlay/usr/share/openipc/customizer.sh

@@ -44,7 +44,8 @@ fw_setenv rmem 19M@0x2D00000
 # Set motor and mmc
 #
 fw_setenv gpio_mmc 61
-#fw_setenv gpio_motors 53 52 54 14 17
+#fw_setenv ptz_control gpio
+#fw_setenv ptz_gpio 53 52 54 14 17
 #
 #
 #adduser viewer -s /bin/false -D -H ; echo viewer:123456 | chpasswd

devices/t23_lite_jooan-q3r-u/general/overlay/usr/share/openipc/customizer.sh

@@ -43,7 +43,8 @@ fw_setenv rmem 19M@0x2D00000
 # Set motor and mmc
 #
 fw_setenv gpio_mmc 61
-fw_setenv gpio_motors 53 52 54 14 17
+fw_setenv ptz_control gpio
+fw_setenv ptz_gpio 53 52 54 14 17
 #
 #
 #adduser viewer -s /bin/false -D -H ; echo viewer:123456 | chpasswd