libplatsupport: refactor more timers

- The following platforms are changed: am335x,
fvp, hikey, rockpro64
- All platforms pass build
- Except for fvp which doesn't have a machine handy,
the other 3 platforms pass sel4test
- For each platform, the ltimer.c and device-specific
code is more intertwined than I would have liked,
including things like device code branching on
`LTIMER` constants, but I think cleaning the
interface is a project for later

libplatsupport: return error if am335x timeout too long

Don't abort in the driver for a client error.

bbone-timer: update timer for mcs

-remove tick calculations and use frequency lib
-fix bug checking wrong irq bit
-update get time to use 64bit counter
-fix race in ltimer
-return correct error
-use UINT32_MAX

trivial: style and licence

Fix bug in am225x dm timer driver

- TISR_OVF_FLAG was actually the flag for all the irqs, so when we
checked for pending overflow irqs we checked for any pending irq
- break the definition up into a flag for each possible pending irq
- add a getter to check if a match irq is pending (the way the ltimer
uses the dmt it needs to check for a match not an overflow anyway)
- only increment the ltimer's ms when getting the time if this match flag is set

Refactor beaglebone timer

- remove pstimer wrappers
- explicitly use dmt, rename variants of dm_timer, dmt, to dmt
- expose dmt interface

fix licenses

libplatsupport: Use stubtimer timeout method

Remove a bunch of duplicated code.

libplatsupport: Expand timer properties

Indicate the types of timeout supported in the properties.

libplatsupport: Use stubtimer timeout method

Remove a bunch of duplicated code.

libplatsupport: Expand timer properties

Indicate the types of timeout supported in the properties.