arm64: tegra21: update tegra21_defconfig

arm64: tegra21: update tegra21_defconfig

Add/remove support for below configs
1. Remove the below configs as most of them are enabled by default.
   CONFIG_PANIC_TIMEOUT unwanted config
   CONFIG_MACH_GRENADA  old config, unused
   CONFIG_TEGRA_CPU_VOLT_CAP  Not applicable for erista
   CONFIG_UID_STAT as this is buggy and not needed
2. Add below config
   CONFIG_INET_AH
   CONFIG_INET_IPCOMP
   CONFIG_LOCKUP_DETECTOR
   CONFIG_DEBUG_KMEMLEAK=y
   CONFIG_DEBUG_KMEMLEAK_EARLY_LOG_SIZE=2000
   # CONFIG_DEBUG_KMEMLEAK_SCAN_ON is not set
   CONFIG_DEBUG_ATOMIC_SLEEP=y
   CONFIG_PREEMPT_TRACER

Bug 200112658
Bug 200112717

Change-Id: Ic8044988eacba3c866b1a4b1c3159741893c3816
Signed-off-by: Bibek Basu <bbasu@nvidia.com>
Reviewed-on: http://git-master/r/757847
Reviewed-by: Automatic_Commit_Validation_User
GVS: Gerrit_Virtual_Submit
Reviewed-by: Venkat Moganty <vmoganty@nvidia.com>