SAMA5 PIO: Fix a typo in Schmitt trigger configuration; Configure pin as a a vanilla input first so that final pin configuration is more read-able (i.e., easier to debug)

SAMA5 TWI: Some restructured needed by up_i2creset.  Also timeout needs to vary with the size of the transfer and if debug is on or not

Use sam_pio_forceclk() so that we can read the current state of an open-drain output in the TWI reset logic.

Add a new interface sam_pio_forceclk() that can be used to force PIO clocking on.  I am afraid I was too conservative with PIO clocking in the initial design; this is the price

SAMA5D3/4 HEAP: Add a configuration option to reserve DRAM for a framebuffer when executing out of DRAM.

NET: emoved all includes of uip.h; added includes of ip.h wherever needed.  Tried to fix problems of the now missing sneak inclusions because uip.h was removed.  There are probably a few of these that were missed.

AMA5 OHCI: Pointers to allocated port values were not being nullified after being deallocated.  This caused some assertions when debug was enabled

SAMA5 OHCI: Fix an error in a DEBUGASSERT statement.  Caused assertion to fire inappropriately when a low- or full-speed device is removed and CONFIG_DEBUG=y

SAMA5D3/4: UPLL divisor to generate 48MHz for OHCI is different from the two families.  No idea why.

CCM PROCFS: Changed the configuration a bit.  I am still not happy about the coupling between procfs, mtd, and now STM32

SAM3/4 and SAMA5 Ethernet:  Fix an error in the function that determines the number of free TX descriptors

SAMA54D-EK:  Don't disable any features in the NSH configuration.  Comments updated in several files