Use "Medium power with Device Initiated PM" as default LPM policy for mobile SATA devices

Before making final decision please consider that some users experience issues with this option. For example: https://bugzilla.redhat.com/show_bug.cgi?id=1571330 , https://bugzilla.redhat.com/show_bug.cgi?id=1578072

Only OEM systems with Ubuntu preloaded use linux-oem kernel. We have QA to rigorously test systems before shipping, so it should be fine for linux-oem users.

This bug was fixed in the package linux-oem - 4.15.0-1012.15

---------------
linux-oem (4.15.0-1012.15) bionic; urgency=medium

  * linux-oem: 4.15.0-1012.15 -proposed tracker (LP: #1782181)

  * Miscellaneous Ubuntu changes
    - Rebase to 4.15.0-29.31

  [ Ubuntu: 4.15.0-29.31 ]

  * linux: 4.15.0-29.31 -proposed tracker (LP: #1782173)
  * [SRU Bionic][Cosmic] kernel panic in ipmi_ssif at msg_done_handler
    (LP: #1777716)
    - ipmi_ssif: Fix kernel panic at msg_done_handler
  * Update to ocxl driver for 18.04.1 (LP: #1775786)
    - misc: ocxl: use put_device() instead of device_unregister()
    - powerpc: Add TIDR CPU feature for POWER9
    - powerpc: Use TIDR CPU feature to control TIDR allocation
    - powerpc: use task_pid_nr() for TID allocation
    - ocxl: Rename pnv_ocxl_spa_remove_pe to clarify it's action
    - ocxl: Expose the thread_id needed for wait on POWER9
    - ocxl: Add an IOCTL so userspace knows what OCXL features are available
    - ocxl: Document new OCXL IOCTLs
    - ocxl: Fix missing unlock on error in afu_ioctl_enable_p9_wait()
  * Critical upstream bugfix missing in Ubuntu 18.04 - frequent Xorg crash after
    suspend (LP: #1776887)
    - ocxl: Document the OCXL_IOCTL_GET_METADATA IOCTL
  * Hard LOCKUP observed on stressing Ubuntu 18 04 (LP: #1777194)
    - powerpc: use NMI IPI for smp_send_stop
    - powerpc: Fix smp_send_stop NMI IPI handling
  * IPL: ppc64_cpu --frequency hang with INFO: rcu_sched detected stalls on
    CPUs/tasks on w34 and wsbmc016 with 920.1714.20170330n (LP: #1773964)
    - rtc: opal: Fix OPAL RTC driver OPAL_BUSY loops
  * [Regression] EXT4-fs error (device sda2): ext4_validate_block_bitmap:383:
    comm stress-ng: bg 4705: bad block bitmap checksum (LP: #1781709)
    - SAUCE: Revert "UBUNTU: SAUCE: ext4: fix ext4_validate_inode_bitmap: comm
      stress-ng: Corrupt inode bitmap"
    - SAUCE: ext4: check for allocation block validity with block group locked

 -- Timo Aaltonen <email address hidden> Wed, 18 Jul 2018 15:56:13 +0300