ARM: dts: at91: sama5d2: Fix the label numbering for flexcom functions

ARM: dts: at91: sama5d2: Fix the label numbering for flexcom functions

The sama5d2 SoC has the following IPs: [uart0, uart4], {spi0, spi1}, {i2c0, i2c1}.
Label the flexcom functions in order:
flx0: uart5, spi2, i2c2
flx1: uart6, spi3, i2c3
flx2: uart7, spi4, i2c4
flx3: uart8, spi5, i2c5
flx4: uart9, spi6, i2c6

Some boards respected this scheme, others not. Fix the ones that didn't.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Link: https://lore.kernel.org/r/20200514050301.147442-2-tudor.ambarus@microchip.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>