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.

Rename pwm_devinit() to board_pwm_setup().  Add CONFIG_BOARDCTL_PWMTEST that will enable calling board_pwm_setup() from boardctl().  Replace calls to pwm_devinit() in apps/examples/pwm with calls to boardctl().  In all configurations that enable the apps/examples/pwm test, make sure that boardctl() suppoprt is properly enabled.

Update several defconfig files.  Make sure that every defconfig file that requires external graphics initialization also approprietly initializes boardctl().

Rename up_nxdrvinit() to board_graphics_setup().  Add CONFIG_BOARDCTL_GRAPHICS that will enabled calls to board_graphics_setup() from boardctrl().  In apps/ and NxWidgts/, replace all calls to up_nxdrvinit with calls to boardctl().

Rename adc_devinit() to board_adc_setup().  Add support to the boardctl() interface so that it can call board_adc_setup() on behalf of an application.  Change apps/examples/adc to that is now calls boardctl() instead of adc_devinit() in order to initalize the ADC device.