SAM3/4 and SAMV7 UART:  The IMR register is read-only.  This means that sam_restoreints() does not actually re-enable UART interrupts.

A side-effect of changing serial settings via TERMIOS (such as tcsetattr) is that serial interrupts were being left disabled.  This is not a problem if the serial configuration is changed when there are no open references to the serial device.  In that case, serial interrupts are disabled and will not be enabled enabled until the serial device is first opened.  But it is fatal if the serial device is already opened and if there is a task waiting to receive data.  In that case, the side-effect of disabling interrupts is fatal:  That task is then left hanging with interrupts disabled.

Implements CONFIG_TIME_EXTENDED as we discussed relative to providing the last 3 members of the tm struct and support for filling them in and even using the wday in the STM32 RTC. From David Sidrane.

Add conditional logic so that people who use F1 don't have to be bother with meaningless RTC MAGIC settings

SAMV7:  Apparently the data sheet is wrong, SDRAM clocking must be enabled at the PMC or the SDRAM does not work!  The data sheet says that there is no clock control for SDRAMC

More renaming: up_lcdinitialize->board_lcd_initialize, up_lcdgetdev->board_lcd_getdev, up_lcduninitialize->board_lcd_uninitialize

SAMV7: Add SMC register definition header file; SAMV71-Xult: Add an LCD driver.  The initial commit is simply the SAVM4E-EK ILI9375 driver will bogus name changes to ILI9488.

rch_tcinitialize() and arch_tcunitinitialize() renamed to board_tsc_setup() and board_tsc_teardown().  These are not long called directly by applications but only indirectly throught the crappy boardctl() OS interface.

SAMV71-XULT: Add option to support connection of the maXTouch Xplained Pro on the 50-pin LCD connector