mmc: jz4740: Add support for the JZ4780

mmc: jz4740: Add support for the JZ4780

Add support for the JZ4780 MMC controller to the jz47xx_mmc driver. There
are a few minor differences from the 4740 to the 4780 that need to be
handled, but otherwise the controllers behave the same. The IREG and IMASK
registers are expanded to 32 bits. Additionally, some error conditions are
now reported in both STATUS and IREG. Writing IREG before reading STATUS
causes the bits in STATUS to be cleared, so STATUS must be read first to
ensure we see and report error conditions correctly.

Signed-off-by: Alex Smith <alex.smith@imgtec.com>
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Tested-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Ezequiel Garcia <ezequiel@collabora.co.uk>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>