m4: defconfig update

SELinux was enabled, but not really, due to CONFIG_SECURITY being set to 'n'.
Manual defconfig editing?

CONFIG_MMC_MSM_SDC3_NEED_PAD_PWR got renamed to CONFIG_MMC_MSM_SDC3_NEED_PAD_PWR,
fix that.
m4: disable pid tracking in contextidr

Kconfig help entry says we need hw trace tools to use this, so...
m4: disable register tracing

Gives a whopping 1M back for userland to use.