MFC: allocate CMA region in low memory

CMA allocations can now go into high memory, but as the MFC ones are
used extensively in the kernel as well as userspace, it makes
more sense for them to be in low memory.
RTL8723BS driver
rtl8723bs: disable ndev notifier

This causes a kernel crash for reasons not yet explored.
odroidu2_defconfig updates

Enable RTL8723BS SDIO wifi
Don't try to include broadcom firmware
Sqwerty: force polling of SDIO slot

Not getting a response from the realtek wifi card, so make it poll,
for easier diagnosis on the hardware side.
Revert "Sqwerty: increase EPLL to 480MHz"

This reverts commit 63593f8119623299c308a78679e4ae473082050d.

There is some instability seen when moving EPLL to 480MHz.

Specifically, while configuring the audio muxes and setting clock rates
in the sound node during boot, the system often freezes.

The issue is somehow timing related, as log messages usually avoid
the freeze, as does loading the sound driver as a module after boot.

I tried inserting delays, setting up the audio clock tree before
linking it to EPLL, setting EPLL as 480MHz from uboot, but wasn't
able to find any reliable way of avoiding the hang other than
going back to 192MHz.
Sqwerty: move Mali to APLL

With EPLL back at 192MHz we need a new high speed clock for Mali.
The next best option is APLL, 1400/3 = 466MHz.

Unfortunately this results in a small performance drop, measuring
es2gears default size at 1080p X display mode:

                    BEFORE    AFTER
RAW X               379       348
MUTTER              209       180
ENDLESS SHELL       129       120
Add more VPLL frequencies

Add high frequencies to test against the Hitachi VGA monitor
at the ODM, to try to get a feel for the maximum pixel clock
of the FIMD.

1600x1200 @ 75Hz : 202.5MHz
1600x1200 @ 85Hz : 229.5MHz
1600x1200 @ 90Hz : 243.0MHz