mmc: sdhci-of-esdhc: Don't walk device-tree on every interrupt

Commit b214fe59

 ("mmc: sdhci-of-esdhc: add erratum eSDHC7 support")
added code to check for a specific compatible string in the device-tree
on every esdhc interrupat. Instead of doing this record the quirk in
struct sdhci_esdhc and lookup the struct in esdhc_irq.

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Link: https://lore.kernel.org/r/20200903012029.25673-1-chris.packham@alliedtelesis.co.nz
Fixes: b214fe59

 ("mmc: sdhci-of-esdhc: add erratum eSDHC7 support")
Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>