[libata] sata_mv: Fix 50xx irq mask
[libata] sata_mv: Fix 50xx irq mask

IRQ mask bits assumed a 60xx or newer generation chip, which is very
wrong for the 50xx series.  Luckily both generations shared the per-port
interrupt mask bits, leaving only the "misc chip features" bits to be
completely mismatched.

Fix 50xx by ensuring we only program bits that exist.

Signed-off-by: Jeff Garzik <f3e731dfa293c7a83119d8aacfa41b5d2d780be9@garzik.org>

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas