usb: xhci: rework Event Ring Segment Table Address mask

usb: xhci: rework Event Ring Segment Table Address mask

Event Ring Segment Table Base Address Register contain two fields:
 - Bits 5:0:	RsvdP (Reserved and Preserved)
 - Bits 63:6:	Event Ring Segment Table Base Address

Currently, an inverted RsvdP mask (ERST_BASE_RSVDP) is used to extract
bits 63:6. Replaces the inverted mask with a non-inverted mask,
'ERST_BASE_ADDRESS_MASK', which makes the code easier to read.

Signed-off-by: Niklas Neronin <niklas.neronin@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20250515135621.335595-20-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>