mmc: sdhci-esdhc-imx: add flag ESDHC_FLAG_ENGCM07207

Just like the use of the flag ESDHC_FLAG_MULTIBLK_NO_INT, let's add
another flag ESDHC_FLAG_ENGCM07207 to enable the workaround for errata
ENGcm07207 and set the flag for i.MX25 and i.MX35 ESDHC.

While at it, let's use BIT() macro for ESDHC_FLAG_MULTIBLK_NO_INT as
well.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Dong Aisheng <b29396@freescale.com>
Signed-off-by: Chris Ball <cjb@laptop.org>