arm_mpam: Keep MBW_MIN close to MBW_MAX

commit 6f87cc48b01d129c525aaa328ef65847364b239f from
git@git.assembla.com:cavium/WindRiver.linux.git

As per ARM MPAM spec (Table 9-1 on page 9-181), preference for the
service request is high as long as used bandwidth is below the
minimum value (governed by MBW_MIN), and it became medium when used
bandwidth is above minimum.

For instance , when we program MBW_MIN to value 0x3 (~2% bandwidth)
even when MBW_MAX is 0xff (100%), preference for the service request
(for high priority task) become medium once used bandwidth crosses
the 2% minimum bandwidth.

In order to ensure service requests from high priority applications
are served with HIGH preference until it reaches the user requested
bandwidth, we keep MBW_MIN closer to MBW_MAX at a difference of 5%.

So, if MBW_MAX is 0xff (100%), MBW_MIN should be 0xF3 (95%). Also,
for MBW_MAX >= 10, MBW_MIN is kept at fixed value 0x3 (~2%).

Signed-off-by: Linu Cherian <lcherian@marvell.com>
Signed-off-by: Amit Singh Tomar <amitsinght@marvell.com>
Change-Id: I8305012344bf76a460244cb64e1c882a5ba08067
Reviewed-on: https://sj1git1.cavium.com/c/IP/SW/kernel/linux/+/74331


Tested-by: Sunil Kovvuri Goutham <sgoutham@marvell.com>
Reviewed-by: Sunil Kovvuri Goutham <sgoutham@marvell.com>
(cherry picked from commit 8afee48fdc875cd7cce416d6a9acc450195202ca)
Reviewed-on: https://sj1git1.cavium.com/c/IP/SW/kernel/linux/+/74524


Signed-off-by: Ruiqiang Hao <Ruiqiang.Hao@windriver.com>