[Nokia][supervisor] add linecard_reboot_timeout value to platform_env…

… for Nokia-IXR7250E platform (sonic-net#18862)

This PR add the platform specified linecard_reboot_timeout value to the platform_evn.conf. It works PR sonic-net/sonic-platform-daemons#480 and sonic-net/sonic-utilities#3292 to address issue sonic-net#18540

Signed-off-by: mlok <marty.lok@nokia.com>

device/nokia/x86_64-nokia_ixr7250e_sup-r0/platform_env.conf

@@ -2,3 +2,4 @@ usemsi=1
 dmasize=128M
 default_mtu=9100
 supervisor=1
+linecard_reboot_timeout=180