[ARM] 3565/1: AT91RM9200 MMC update

Patch from Andrew Victor

This patch includes code cleanups and minor fixes to the AT91RM9200 MMC
driver.

1. Replace calls to DBG() with pr_debug().
2. 'host' can never be null, so don't bother checking for that case.
3. Remove SA_SAMPLE_RANDOM from request_irq().  [Patch from Matt
Mackall]
4. clk_get() doesn't return NULL on error - need to test returned value
with IS_ERR().
5. Free resources if clk_get() or request_irq() fails.
Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>